Study of atmospheric pressure. Study of natural phenomena: changes in atmospheric pressure, the approach of rain. Influence on the weather

STATE BUDGETARY EDUCATIONAL INSTITUTION

PROFESSIONAL EDUCATION OF THE ROSTOV REGION

"KAMENSKY TECHNIKUM OF CONSTRUCTION AND AUTOSERVICE"

Search and research work

on this topic:

"Pressure is obvious and necessary"

Completed:

learning groups number 14

Bulgakov Alexander

Khomenko Alexander

Leaders:

Physics teacher Semikolenova

Natalya Anatolyevna

Master p / o Myachin Viktor Mikhailovich

Kamensk-Shakhtinsky

2014

Content

Introduction ……………………………………………………………………… ..

1. Description and course performance of work…. ……………………… .. ……………… ..

1.1. The history of the study of "Pressure" ………………………………………….….

1.2. Pressure measuring instruments …………………………………… ..

1.3 Types of pressure gauges ……………………………………………………… ...

1.4 Factors affecting tire reliability ………. ………………………….

…………………………………………………..

2.1 Experiments on demonstrating pressure …………………………………………

2.2 Experiments to demonstrate the practical use of pressure ………

2.3 Tire pressure and temperature ……… .. …………………………… ........

Conclusion ………………………………………………………………………….

Literature …………………. ……………………………………………………….

Appendices ………………………………………………………………………….

Introduction

The pilots say that the air is what gives support to our wings. Airplanes could not fly without air. Doctors say that air is what we breathe. You can't live without air! And the engineers say: “Air is a wonderful worker. True, he is free, flying, you cannot grab him. But if you collect it, lock it in a suitable container and squeeze it well, it can do a lot. "

The action of various pneumatic devices is based on the use of air, it opens and closes doors in buses, trolleybuses and trains, it softens all shocks and shocks on uneven tracks. One of the most important problems facing road transport is increasing the operational reliability of vehicles. The solution to this problem, on the one hand, is provided by the automotive industry through the production of more reliable cars, on the other hand, by improving the methods of technical operation of cars.

Pressure is one of the most important parameters of various processes. That is why our search and research project is called: "Pressure - Obvious and Necessary".

The problem of our research is the obvious manifestation of gas pressure and the expediency of its use in various spheres of human activity.

The contradictions in our research work are between the perception of pressure as a given and the lack of experience in explaining the phenomena around us; between the need to use pressure and the lack of such experience.

The object of our research is pressure.

The subject of the research is a set of experiments that contribute to the demonstration of atmospheric pressure and its practical use.

The aim of our study is to demonstrate atmospheric pressure and its application, both at the household and professional level.

To carry out the search and research work, we had to solve a number of tasks in several directions:

to study historical facts on the accumulation and systematization of knowledge about "Pressure";

prepare a table of units of measurement for a given physical quantity;

examine pressure measuring devices:

• • select from among them those that are applicable to our profession;

    study the device and principle of operationpressure measuring instruments;

identify factors affecting the change in pressure incar tires;

select a set of experiments that clearly show the existence of atmospheric pressure and its practical application in everyday life and profession190631. 01 "Auto mechanic";

to form a material and technical base for conducting and demonstrating experiments;

build a graph of pressure incar tires from air temperature;

During the implementation of the project, we used the following research methods:

experience, observation, analysis, generalization and systematization of information obtained as a result of working with various sources of information and conducting experiments.

As hypotheses of our prospecting and research work, we have identified: demonstration of pressure manifestation and its practical and professional use and the assumption that systematic monitoring of wheel pressure will significantly increase the service life of automobile tires.

In our work, we have identified the following stages of research:

Preparatory;

Basic:

search and research;

evaluative and reflective;

Final

Description and progress of the study

In the classroom "Physics", studying the section "Fundamentals of Molecular-Kinetic Theory", we got acquainted with the manifestation of gas pressure. We found this topic interesting for in-depth study. The topic of the search and research work was determined by: « The pressure is obvious and necessary ”, identified a number of tasks and started to solve them.

To begin with, we decided to study the historical aspect of this issue. We wanted to know which of the scientists accumulated and systematized knowledge about pressure.

1. History of the study of "Pressure"

The existence of air has been known to man since ancient times. The Greek thinker Anaximenes, who lived in the 6th century BC, considered air to be the basis of all things. At the same time, air is something elusive, as if immaterial - “spirit”.

In the early Middle Ages, an idea of ​​the atmosphere was expressed by the Egyptian scientist Al Khaisama (Algazena). He not only knew that air has weight, but that the density of air decreases with height.

Until the middle of the 17th century, the assertion of the ancient Greek scientist Aristotle that water rises behind the pump piston was considered indisputable because "nature is afraid of emptiness.".

This statement in 1638 led to confusion when the idea of ​​the Duke of Tuscany to decorate the gardens of Florence with fountains failed - the water did not rise above 10.3 m.

The perplexed builders turned to Galileo for help, who joked that nature probably really does not like emptiness, but up to a certain limit. The great scientist could not explain this phenomenon.

His student, Torricelli, after long experiments, proved that air has weight, and the pressure of the atmosphere.

In 1648, Blaise Pascal's experiment on the Pew-de-Dôme proved that a smaller column of air exerts less pressure. Due to the attraction of the Earth and insufficient speed, air molecules cannot leave the near-earth space. However, they do not fall to the surface of the Earth, but hover above it, as they are in continuous thermal motion.The unit of measurement is named after him. pressure (mechanical stress) in the international measurement system - Pascal (designation: Pa). There are also other units of measurement of this physical quantity (see Appendix 1).

Otto von Guericke, the burgomaster of the city of Magdeburg, was engaged in a lot and fruitful study of atmospheric pressure. In May 1654, he delivered an experiment that was clear evidence of the existence of atmospheric pressure.

For the experiment, two metal hemispheres were prepared (one with a tube for evacuating air). They were put together, and a leather ring soaked in molten wax was placed between them. A pump was used to evacuate air from the cavity formed between the hemispheres. Each of the hemispheres had a solid iron ring.
Two eights of horses harnessed to these rings pulled in different directions, trying to separate the hemispheres, but they failed. When air was allowed into the hemispheres, they disintegrated without external effort.

1.2 Instruments for measuring pressure

The ability to measure atmospheric pressure is of great practical importance. This knowledge is necessary in weather forecasting, in medicine, in technological processes and the life of living organisms. For these purposes, a large number of different devices are used, which can be divided into:

a) manometers - for measuring absolute and gauge pressure;

b) vacuum gauges - for measuring the vacuum (vacuum);

c) manovacuum meters - for measuring excess pressure and vacuum;

d) pressure gauges - for measuring low excess pressures (the upper measurement limit is not more than 0.04 MPa);

e) traction meters - for measuring small discharges (the upper measurement limit is up to 0.004 MPa);

f) traction pressure gauges - for measuring discharges and small overpressures;

g) differential pressure gauges - for measuring the pressure difference;

h) barometers - for measuring the barometric pressure of atmospheric air

The use of various types of measuring instruments allows you to measure pressure from 10 to 10 −11 mbar.

1.3 Types of pressure gauges

Maintaining the correct tire pressure is one of the main rules for operating a car. We have dedicated the next point of our work to solving this problem.

Manometers are used in all cases when it is necessary to know, control and regulate pressure.

Manometers are subdivided according to accuracy classes: 0.15; 0.25; 0.4; 0.6; 1.0; 1.5; 2.5; 4.0 (the lower the number, the more accurate the device).

There are various types of pressure gauges for measuring the air pressure in tires.The simplest option for a tire pressure monitoring sensor is a mechanical sensor.

They can be arroware quite accurate, but they are "afraid" of falls and overloads with high pressure, due to which the gauge spring inside the gauge deteriorates.

Mechanical pressure gauges in the form of a "handle" with a coil spring are much more reliable, but, as a rule, have a lower measurement accuracy.

The pressure sensor in the form of caps is put on the tire nipple. Its principle of operation is the mechanical movement of the piston depending on the pressure.

At a nominal pressure of the sensor of 2 bar, a green color is visible on this device. If the pressure drops to 1.7 bar, a yellow indicator appears. When the tire pressure reaches 1.3 bar or less, the indicator turns red.

Electrical sensors are more accurate and more difficult to install. For a passenger car, an electric tire pressure sensor looks like a set of four devices that monitor the pressure, and sometimes temperature, in the tires and have one receiving and information (main, main) unit.

These 4 sensors communicate with each other using radio communication, that is, the signal is sent to the main unit, which displays information on the display in the car. To ensure that the service life of the electric vehicle sensor is not too short, signals are sent to the unit every 15 minutes while the vehicle is parked, and after 5 minutes while the vehicle is in motion. But in the case of a change in pressure (more than 0.2 kgf / cm 2 ), the sensor switches automatically to intensive measurement and data transmission mode.

Electric sensor installed on car rims. To install them, the tire is disassembled and the sensor is mounted directly on the disc rim near the nipple, then the tire is put in place and balanced taking into account the weight of the sensor, because its weight is about 30 grams. The disadvantage of such a device can be attributed only to the complexity of the installation, and the advantages - the high tightness of the system.

Electrical pressure sensors - microchips. Microchips are very complex because a chip is installed inside the tire, which contains all the information about the tire, that is, its type, size, load capacity, maximum speed, recommended pressure and date of manufacture. All this is carried out at the manufacturing plant. Such a system is able to recognize any changes in the tires and immediately report them to the driver (with the ignition on).

As you can see, the range of tire pressure sensors is quite wide, this allows each driver to choose exactly the device that best suits his needs (Appendix 2).

1. Factors affecting tire reliability

The tire is one of the main elements of the car and significantly affects its performance. The traction and braking characteristics of the machine, its stability, traffic safety, smooth running, and economy depend on tires.

There are two main factors that significantly affect tire pressure. These are the ambient and load temperatures. In our work, we will pay attention to the first of them.

On some car tires, the recommended pressure is indicated so that the driver can see at what pressure they remain functional, that is, they do not collapse.

It is important that the air pressure, within known limits, can easily vary from operating conditions, as a result of which the tire drift resistance during vehicle operation can be influenced in a desirable manner.

Weather conditions have a significant effect on tire pressure. The air pressure in the tires changes with a sharp change in weather, from the temperature of asphalt hot during the day in the sun, from an increase in the temperature of the wheels due to friction forces.

In a tire inflated according to the instructions (Appendix 3), the air pressure contributes to an even distribution of the load in the contact patch, which ensures the stability of the tire structure. It is known that this affects the nature of its wear, rolling resistance and durability.

If the tire pressure is too high, the vehiclebecomes more rigid, the load on the suspension units increases. At the same time, the braking distance increases - all this is due to a decrease in the contact area of ​​the tire with the road..

On an under-inflated tire, the shoulder area wears out faster than the middle of the tread (fig. 1).

The reduced pressure makes the wheel softer and the ride more pleasant, as it absorbs all the bumps in the road. This reduces the elasticity of the tire, accelerates its wear, and increases fuel consumption. The tire creates an uneven distribution of pressure on the road surface, it heats up more, its carcass is destroyed. In addition, aquaplaning and wet grip deteriorate.

Fig. 1 Wear of tires at different pressures

In connection with the foregoing, it can be concluded that forces, different in value and direction, act on the tire during rolling, which in turn largely depend on the external load and the ambient temperature.

2. Experiments that clearly show the existence of atmospheric pressure and its practical application

2.1 Pressure Demonstration Experiments

To implement this point of work, we have selected a set of experiments, a material and technical basis for their implementation and demonstration of the existence of atmospheric pressure and its practical application in various spheres of human activity.

Experience number 1

Equipment: a glass of water, a sheet of thick paper.

Carrying out: The glass was filled to the brim with water and covered with a sheet of paper. Supporting the sheet with your hand, they turned the glass upside down. They took their hand away from the paper - the water does not pour out of the glass. The paper remained as if glued to the edge of the glass.

Explanation: the atmospheric pressure is greater than the pressure produced by the water, so the water is held in the glass.

Experience number 2

Equipment: two funnels, two identical clean dry plastic bottles with a capacity of 1 liter, plasticine.

Carrying out: We took a bottle without plasticine. Poured some water into it through a funnel. A little water flowed into the bottle with the funnel fixed with plasticine, and then it stopped flowing altogether.

Explanation: Water flows freely into the first bottle. Since it replaces air in it, which comes out through the cracks between the neck and the funnel. A bottle sealed with plasticine also contains air, which has its own pressure. The water in the funnel also has pressure, which is due to the force of gravity pulling the water down. However, the force of the air pressure in the bottle exceeds the force of gravity acting on the water. Therefore, water cannot get into the bottle.

Experience number 3

Equipment: ruler 50 cm long, newspaper.

Carrying out: put the ruler on the table so that a quarter of its length hangs over the edge of the table. Place the newspaper on the part of the ruler that is on the table, leaving the hanging part open. Did one hit of karate on the ruler - the ruler cannot lift the newspaper or breaks.

Explanation: Above the newspaper is pressured by atmospheric air. The air pressure on the newspaper above is greater than below, and the ruler breaks .

Experience number 4

Equipment: baking dish, water, ruler, gas or electric stove (should only be used by an adult), empty tin, tongs.

Carrying out: They poured about 2.5 cm of water into the mold. We put it next to the stove. Poured some water into an empty soda can so that the water only covers the bottom. The assistant then heated the jar on the stove. They allowed the water to boil strongly, for about a minute, so that steam came out of the can. They took the jar with tongs and quickly turned it into a mold with water. The tin flattened as soon as water touched it .

Explanation: The can is crumpled due to changes in air pressure. A low pressure is created inside it, and then a higher pressure crushes it. An unheated jar contains water and air. When water boils, it evaporates - it turns from a liquid into hot water vapor. Hot steam replaces air in the can. When an assistant lowers an inverted can, air cannot return to it. Cold water in the mold cools the steam trapped in the can. It condenses - turns from gas back to water. The steam that occupied the entire volume of the jar turns into just a few drops of water, which takes up significantly less space than steam. A large empty space remains in the can, practically not filled with air, so the pressure there is much lower than the atmospheric pressure outside. The air presses on the outside of the can, and it crumples.

These and many other experiments are indeed proof that atmospheric pressure exists and has an impact on us and the objects around us.

2.2 Experiments to demonstrate the practical use of pressure

Many natural processes and actions for us are based on the existence of atmospheric pressure, we will give examples of some of them.

Experience number 5

Equipment: straw, glass of drinking water.

Carrying out: we bring a glass of water to our mouth and "draw in" the liquid

Explanation: When we drink, we expand the rib cage and thereby thin the air in the mouth; under the pressure of the outside air, the liquid rushes into the space where the pressure is less, and thus penetrates into our mouth.

Experience number 6

Equipment: a jar filled with water, a trough.

Carrying out: fill the jar with water. In the inverted form, we install it in a trough so that the neck is slightly below the water level in it. Received an automatic bird drinker.

Explanation: when the water level drops, some of the water will pour out of the bottle.

Experience number 7

Equipment: depicts a liver device, used for taking samples of various liquids, a pipette, a capillary, a cone.

Carrying out: the liver is dipped into the liquid, then the upper hole is closed with a finger and removed from the liquid. When the top hole is opened, liquid begins to flow out of the liver

Explanation: when the upper opening is closed, the atmosphere only exerts pressure from the bottom, otherwise it squeezes the liquid out of the liver.

Experience number 8

Equipment: 1- polyethylene bag, 2- glass tube, 3- rubber balloon, 4- two rings made of thick wire, 5- threads.

Explanation: Breathing model. When the plastic bag is deformed, a change in the volume of the rubber ball is observed. Similar processes occur when breathing.

We have given some examples of the use of atmospheric pressure in everyday life (see Appendix 4), the manifestation of such in our professional activity will be considered in the next paragraph of our work.

2.3 Tire pressure and temperature

We carried out a series of experiments establishing the relationship between pressure and temperature. The results of the experiments are presented in tabular and graphical form.

1 day

Temperature, 0 С

Pressure, bar

2,15

2,25

2,30

2nd day

Temperature, 0 С

Pressure, bar

2,16

2,26

2,31

Day 3

Temperature, 0 С

Pressure, bar

2,25

2,32

Correctly set tire pressure increases tire life and also ensures safe driving. A driver who cares about his own safety and the safety of his car should install tire pressure sensors. These electronic monitoring systems constantly monitor the pressure and temperature inside the tires so that any wheel malfunction can be tracked.

Conclusion

In the course of our research, we found out how important the knowledge of the existence of atmospheric pressure is, that nothing but atmospheric pressure can explain the course of many physical phenomena. We were surprised that it is atmospheric pressure that determines many processes in human life and activities. In addition, the factors influencing the efficiency of car tire operation were identified. determined that the pressure in the tires affects the traction, braking, characteristics of the machine, its stability, road safety, ride comfort, efficiency, and the duration of the tires themselves.

We studied the principle of operation, the advantages and disadvantages of each type of pressure sensor in car tires.

Based on the results of search and research work, in order to improve traffic safety and vehicle performance, we are ready to formulate recommendations for the implementation of its potential properties:

strictly follow the instructions for using car tires recommended by the manufacturer;

systematically diagnose tire pressure, while taking into account weather conditions;

carry out an additional inspection of the car before long trips.

In connection with the above, it can be concluded that pressure helps to carry out many physiological processes, is necessary for specialists of various professions, requires systematic monitoring and correction.

This work deepened our knowledge of "Pressure", expanded our understanding of the spheres of its manifestation and application. In addition, we consider it expedient to continue the study of the effect of pressure on other vehicle components.

Literature

Bilimovich B.F. "Physics quizzes in high school” Publishing house "Education", Moscow 1968

Kalissky V.S. Automobile. Third-class driver's textbook. M. Transport, 1973

Kamin A.L .. Physics. Developmental training. A book for teachers. - Rostov-on-Don: "Phoenix", 2003.

Nize G. Games and scientific entertainment. - M .: Education, 1958.

Perelman Ya. I. Entertaining physics: book 1. - M .: OOO "AST Publishing House", 2001.

Fundamental research // scientific journal №8, 2011

Electronic resources of remote access

znaj .net

Annex 1

Pressure units

Pascal
(Pa, Pa)

Bar
(bar, bar)

Technical atmosphere
(at, at)

Physical atmosphere
(atm, atm)

Millimeter of mercury
(mmHg.,

mmHg, Torr, torr)

Pound force
per sq. inch
(psi)

1 Pa

1 N / m 2

10 −5

10.197 10 −6

9.8692 10 −6

7,5006 10 −3

145.04 10 −6

1 bar

10 5

1 10 6 dyne / cm 2

1,0197

0,98692

750,06

14,504

1 at

98066,5

0,980665

1 kgf / cm 2

0,96784

735,56

14,223

1 atm

101325

1,01325

1,033

1 atm

760

14,696

1 mm Hg

133,322

1.3332 10 −3

1.3595 10 −3

1.3158 10 −3

1 mm Hg

19.337 10 −3

1 psi

6894,76

68.948 10 −3

70.307 10 −3

68.046 10 −3

51,715

1 lb / in 2

Appendix 2

Tire pressure monitoring sensors

Spring-type dial gauge

(gauge tube)

Mechanical pressure gauge (coil spring)

Mechanical pressure gauge in the form of caps,

who dress on the tire nipple

Electrical sensors and

receiving and information unit

Electrical sensor,

installed on auto disks

Electrical pressure sensors - microchips

1 - valve; 2 - wheel rim; 3 - chip; 4 - bus

Appendix 3

Technical characteristics of some cars

Machine brand

kgf

pressure, kgf / cm 2

kgf

pressure, kgf / cm 2

ZIL 130

3000

3000

MAZ-543

5000

5000

URAL-375D

2500

3,2

2500

0,5

Machine brand

Tire size

Tire pressure kg / cm 2

Front wheels

Rear wheels

ZIL-130

9,00-20

3,50

5,30

260-20

3,50

5,00

260-508R

4,5

5,5

GAZ-21 "Volga"

6,70-15

1,70

1,70

185-15R

1,90

1,90

Appendix 4

Using atmospheric pressure

Medicine

pipettes, cans, syringes, liver

In human life

children's toys with suction cups, soap dishes with suction cups, plunger, canning, fountains, fluid intake with a hose, bones of the hip joints.

In nature

snowflakes of different shapes

In animal life

octopus, leeches, flies - suckers, compound hooves of pigs, ruminants, elephant trunk

Agriculture

barometric drinker, milking machines, liver, piston liquid pump.

Meteorology

weather prediction, folk signs, natural "barometers"

“How many wonderful discoveries we have
Prepare the spirit of enlightenment
AND an experience, son of difficult mistakes,
And a genius, a friend of paradoxes ... "
A.S. Pushkin

RELEVANCE OF THE PROBLEM

It was not in vain that I took the lines of the great Russian poet A.S. Pushkin as an epithet, because the study of most sciences is impossible without setting up experiments.
From the textbook "The World Around" I learned about many amazing natural phenomena. I wanted to make models of natural phenomena and conduct experiments with them. Having become interested, I got acquainted with these phenomena from the literature in more detail. I decided to conduct experiments myself. I had to show creative thought and ingenuity.

I have chosen two natural phenomena:
* Atmosphere pressure.
* Atmospheric precipitation (rain).

There is an atmosphere around our globe. The atmosphere is a mixture of various gases, mainly nitrogen (78%) and oxygen (21%). The atmosphere presses on the surface of the Earth. But the influence (pressure) of the atmosphere cannot be seen with the eyes. We can only feel it when the state of our health changes. And how not easy for a person to understand and study what cannot be seen. A device - a barometer - can help with this. It measures atmospheric pressure. But modern barometers are very complex and show digital changes in the atmosphere. I have constructed a mock-up of the simplest barometer. It allows you to see the effect of atmospheric pressure on the membrane of the device and makes this phenomenon from invisible, quite real (visible).

More than 70% of the Earth's surface is covered with water. Of the total amount of water, 1% is in the atmosphere, 97% in the oceans, and the rest in rivers, lakes and glaciers. Under the influence of solar heat, water evaporates and rises into the air. The air contains this invisible water vapor. The amount of water vapor in the air is characterized by the humidity indicator. Rising upward, the water vapor cools and collects into tiny water droplets, forming clouds. When the droplets become large enough, they fall as precipitation (rain or snow). The higher the humidity, the greater the likelihood of cloud formation and precipitation. So, having established empirically, the increase in humidity in the atmosphere, we can predict rainfall. I put together a Rain Detector based on the effect of moisture in the atmosphere.

Setting up experiments is a very exciting experience. All the experiments I have carried out are simple and carried out with the implementation of safety precautions, which is important for those who conduct experiments at home, especially for the first time. I describe the preliminary preparation and the stages of implementation, which allows in the future to accurately handle the objects and to properly organize the plan of their work. In addition to the studied natural phenomena, in these experiments one can simultaneously get acquainted with the laws of physics (electricity) and acquire technical skills (soldering, assembling an electrical circuit, working with a screwdriver). It is always useful for a man.

Thus, the studied information material and our own experiments conducted on its basis formed the basis of this work, defining its goal, objectives and conclusions.

PURPOSE OF THE STUDY:

Setting up experiments to study the phenomena of the surrounding nature.

RESEARCH OBJECTIVES:

* Conduct observations of the phenomena selected for experiments in nature (weather changes, precipitation);
* Develop and conduct experiments;
* Take pictures of the results obtained;
* Give recommendations for setting up experiments.

OWN RESEARCH

Layout of my barometer (Experiment # 1).

Experience material: can, balloon, juice tube, scotch tape and cardboard.

I cut off the balloon and pulled it over the jar. The result is a stretched membrane. I secured the ball on the neck with an elastic band. I made an arrow out of a juice tube, sharpening its end. Tape one end of it in the middle of the ball covering the jar. The arrow should be located strictly horizontally. I put a piece of cardboard next to the jar so that the outer end of the arrow barely touched it, and marked the position of its tip in red (atmospheric pressure at the beginning of the experiment). I drew a scale along this line. I glued this piece of cardboard to the jar with duct tape and watched the position of the arrow.

With an increase in atmospheric pressure, the surface of the ball was pressed into the vessel, as it were, and the arrow rose up the scale.

When the atmospheric pressure dropped, air from the can was pressed on the surface of the ball from the inside, tending upward, and lifted the ball.

The arrow went down the scale. You cannot see the exact indicators of atmospheric pressure on such a barometer, since the membrane of the stretched ball is not thin and sensitive enough. The tube goes down and up by only one division, but the rise and fall of atmospheric pressure can be seen very well. These results matched the weather announcements in the local newspaper.

Observations have shown: With increasing atmospheric pressure, the weather was clear, sunny. When the pressure drops, it is cloudy, sometimes rainy.

My next experience is devoted to the study of atmospheric precipitation (rain). The clouds have gathered. It will rain soon. How to find out about it in time? A rain detector will help me.

Construction of the model "Determinant of rain" (Experiment No. 2).

Experience material: clothespin, electric wire (about 2m so that the wire reaches the window), 2 "finger" batteries, a flashlight bulb, 2 screws, lump sugar.

I screwed 2 screws into the clothespin from different sides. I attached (soldered) the stripped ends of the wire to them. I fixed a piece of sugar between the ends of the clothespin, so that the electrical circuit would not be closed.

I assembled an electrical circuit “rain detector”: I connected in series a wire from a clothespin with a battery and a light bulb.

I stuck my clothespin with a lump of sugar out the window into the street. With high air humidity (humidity is the amount of water in the atmosphere), which occurs before the rain, sugar gradually absorbs water, crumbles and breaks down. The contacts are closed and the lamp lights up.

According to my observations, after about 30 minutes. it started to rain.

CONCLUSIONS

1. Atmospheric pressure, rain - these are phenomena that are subject to clear laws of nature, which can be observed and studied.
2. The experiments carried out make it possible to better understand these laws.
3. Photographs and experimental models confirm this study.
4. Recommendations for setting up experiments, I will help to carry them out independently.

Based on the results obtained in the course of the work carried out, a set of recommendations for novice experimenters has been developed:

* all substances and materials used must be available and safe for health;
* when setting up the experiment "model barometer", you must use a large container with a wide neck, to create a thinner and more sensitive membrane
ball when pulling and more air in the can for a better visualization of the experience; the tube should be as thin and light as possible;
* when setting up the experiment "rain detector", you need to use a 3V battery or two 1.5V batteries; you can use an electric bell instead of a light bulb (or a small transistor that runs on batteries and turns on on a musical wave), the electric circuit is assembled in series, the stripped ends of the wire are better soldered, for the strength of the contacts.

CONCLUSION

It is not difficult to carry out these experiments, but it is interesting. They are safe, simple, and helpful. My barometer warns my grandmother of a change in atmospheric pressure, and she takes her medicine on time. I won't be caught off guard by the rain. New Research Ahead!

BIBLIOGRAPHY

* Children's encyclopedia “I want to know everything” // M. “Planet of childhood” - 2003.– pp. 260–261.
* New encyclopedia of schoolchildren // - M. “Makhaon” .– 2009.– P. 128 - 129.

Dashevsky Gleb
Lyceum, grade 3
MOU-Lyceum (Physics and Mathematics), Vladikavkaz

In a healthy person, the systolic and diastolic indicators of the heart should be within the established framework.

Allocate the upper (systolic) and lower (diastolic) blood pressure. The normal high blood pressure level is from 110 to 140 mm Hg. Art., and the lower limit is not less than 70. But the indicators do not always correspond to the established norm, this is due to the individual characteristics of the organism. This should not affect the general well-being; only a doctor can confirm the deviations characteristic of a person.

For each age, experts have determined the boundaries of blood pressure. These indicators are shown in the table:

Monitoring indicators

Also, the doctor has the ability to identify the disease in people who, thanks to single measurements, believe that they have normal blood pressure.

For monitoring, special modern devices are used that can store in memory more than 100 measurements of pressure and heart rate, indicating the date and time of the study.

After measurements have been taken while standing, sitting or lying down, the data is transferred to a computer, where the results are processed using a special computer program.

How to correctly interpret the readings of the monometer will be told by the guests of Elena Malysheva in the video in this article.

Indicate your pressure

Recent discussions.

When blood pressure rises, it always makes you think about the overall health of the whole body. Especially if this happens often, and the tonometer at the same time shows a significant deviation from the norm. In this case, an appropriate diagnosis is made - hypertension. But the worst case scenario is when the pressure suddenly rises. This development of events can lead to a hypertensive crisis, an extremely dangerous condition. Why is there such instability in the work of the cardiovascular system? What provokes a sharp increase in blood pressure? The reasons can be very different, and they are divided into two groups: external factors and internal.

The mechanism for increasing blood pressure is very complex. This process depends on the volume and consistency of blood, the state of blood vessels and heart muscle, as well as on the work of the internal blood flow regulation system. Various factors can trigger this mechanism. The following external prerequisites can lead to a sharp rise in the tonometer indicators:

Gross violation of the rules of a healthy lifestyle.

Prolonged sedentary work or "sofa" pastime provoke blood stagnation, circulatory disorders, and vascular weakness. Low mobility leads to excess weight, which aggravates the pathology of the vascular system.

Abuse of junk food (high in fast carbohydrates, cholesterol, salt, hot seasonings) will lead to clogging of blood vessels, metabolic disorders, increased tone of the vascular walls.

Chronic overwork for several days and lack of proper rest can cause a sharp vasospasm.

Changing weather conditions can also increase the level of blood exposure to blood vessels.

A proven fact is the relationship between blood pressure and atmospheric pressure. There is a directly proportional relationship between them. Most often, along with an increase in atmospheric pressure, a rise in the lower marks of the tonometer in a person is observed. When the atmospheric front is unstable, meteorological people on this day feel a sharp deterioration in their well-being, as the oxygen content in the blood changes.

The emotional factor is considered by many experts to be the main reason for the increased level. It is the central nervous system that plays the main role in the regulation of vascular activity and the speed of blood flow. If she is constantly in tension, the tone of the vessels increases, adrenaline makes them narrow. Vascular resistance to blood flow can increase dramatically.

Extra pounds significantly impair the work of blood vessels. This is enough for the pressure to rise unexpectedly. Fat deposits are formed not only in the form of a large abdomen or ugly folds on the sides, but also inside the organs and in the vessels themselves. Atherosclerosis develops, and this is one of the first reasons for the increased parameters of the tonometer.

As a rule, the development of essential (primary) hypertension is caused by external causes. The overwhelming majority of people are faced with exactly this (95% of the total number of incidents). Hypertension of secondary origin is quite rare.

What to do

Usually, a person who suspects a surge in blood pressure immediately takes up a tonometer to find out its value. If the pressure really increased or, conversely, fell, the question immediately arises of what to do with it and how to treat it.

Many hypotensive patients take tonic drugs that have already become habitual (ginseng, eleutherococcus), drink coffee and tea to improve their well-being. The situation is more complicated with hypertension, when it is no longer possible to reduce the pressure with "improvised" means. Moreover, self-medication and adherence to traditional medicine for such patients is dangerous.
in view of the possible complications of hypertension described above.

In case of any fluctuations in pressure, you should visit a doctor, first of all, going to a therapist.
If necessary, he will recommend a consultation with a cardiologist, urologist, endocrinologist, ophthalmologist or neurologist. To confirm pressure surges, it is necessary to systematically measure it and record the readings. It is possible that after the fact of the presence of arterial hypertension will be established. When the reason for the surges will be clear, the doctor will be able to determine the effective therapy.

It is impossible to say unequivocally which is worse - hypotension or hypertension. Both conditions can be corrected subject to examination and appropriate treatment. It is only clear that an increase in pressure is much more dangerous than hypotension, which has become habitual for a hypotonic person. A hypertensive crisis can cause a stroke, myocardial infarction, acute heart failure and other serious conditions, so at the first sign of pressure surges, you should go to the doctor.

Folk remedies for the treatment of pressure surges

Broth of oats

Rinse a glass of oats, fill it with a liter of filtered, or better distilled water at room temperature and leave for 10 hours. Then simmer over low heat for half an hour. After removing from heat, wrap and leave for another 12 hours. Strain and add up to 1 liter of boiled water.

Take 100 ml daily three times a day for one and a half months. After graduation, take a month break and repeat the course. And this should be done throughout the year. In addition, this remedy is very effective for stomach and duodenal ulcers and chronic pancreatitis.

Garlic

It is an old proven remedy. Peel the head of garlic, wipe it, put it in a jar and fill it with a glass of unrefined sunflower or olive oil. Insist for a day, shaking from time to time (after 4-6 hours). Pour in the juice of one lemon and stir. Insist in a cool place for a week, shaking every other day. Take 1 teaspoon 20 minutes before meals 3 times a day. The course of treatment is 2 months, then a break for a month and the treatment is repeated again.

Mummy

Every day on an empty stomach (in the morning) take 1 tablet (0.2 g) of mummy for 10 days with 3 sips of milk. Take a break for a week and repeat the course. It is better to conduct at least 4 such courses.

Important!
You should be very careful when taking pressure-reducing drugs during a hypotonic state. The pressure can either drop sharply, or if you refuse to take drugs that reduce pressure, it can increase sharply and a crisis will occur. That is, the solution to this issue must be resolved by an individual search method and always with the participation of a doctor.

That is, the solution to this issue must be resolved by an individual search method and always with the participation of a doctor.

It should be borne in mind that preparations based on St. John's wort, motherwort, valerian, nettle (including valocordin) with pressure surges should not be taken (!) - they increase the viscosity of the blood and its tendency to thrombus formation, worsen the blood flow through the arteries and, therefore , increase the pressure.

Why is there an imbalance in the blood pressure regulation mechanism?

There are three mechanisms for regulating pressure:

1. Fast
   • vascular reflexes;
   • Cushing's reaction under the influence of cerebral ischemia;
2. Slow
3. Long-term

The following factors can disrupt the regulation of blood pressure:

• pathology of the endocrine system;
• atherosclerotic vascular changes;
• renal failure;
• osteocondritis of the spine;
• neurological disorders;
• ischemia;
• premenstrual syndrome;
• infections;
• climate change, air travel;
• overdose of caffeine, smoking, alcohol intake;
• different types of anemia;
• adverse reactions to taking medications.

Violation of regulation leads to the fact that the pressure jumps - then high, then low: we will consider the causes and treatment of this phenomenon below.

Mineral corticoids - hormones of the cells of the adrenal cortex, such as aldosterone, are involved in water-electrolyte metabolism, increasing the absorption of water in the kidneys.

Any hormonal imbalance can cause fluctuations in blood pressure: pressure jumps during the day - sometimes high, then low. Therefore, it is worth doing a blood hormone test once a year.

In case of impaired renal function, significant fluctuations in blood pressure can be noted, since they are involved in the release of renin, a substance that triggers a cascade of biochemical reactions in the renin-angiotensin system. This substance is synthesized by kidney cells with a decrease in blood pressure and is one of the effective regulatory mechanisms. In renal failure, the release of renin is impaired, and the regulation mechanism gets lost. As a result, the pressure jumps - then low, then high. Pressure is most often determined by the efficiency of the kidneys.

Osteochondrosis, curvature of the spine, intervertebral hernias strongly affect the blood supply: the displacement of the vertebrae and their degenerative changes can affect the blood flow. This is especially pronounced in cervical osteochondrosis - the arterial networks passing through the neurovascular bundle are pinched. There is oxygen starvation of the brain, the result is a reflex increase in blood pressure to improve blood circulation in the brain, from which the pressure jumps - sometimes low, then high.

Congenital or acquired heart disease

This is reflected in the level of pressure, especially systolic blood pressure - hypertension occurs due to deterioration of the blood supply to the organs of the systemic circulation. At the same time, blood pressure jumps: high upper and low lower.

Acute respiratory infections can cause both high and low blood pressure. Intestinal infections, accompanied by vomiting and diarrhea, usually lead to a drop in blood pressure due to imbalance in water balance and a decrease in blood volume. This is a rather dangerous syndrome: under the supervision of a doctor, it is necessary to gradually replenish the amount of lost fluid in order to normalize blood pressure and overcome dehydration.

It is not for nothing that the system of regulation of body functions is called neurohumoral - hormones are directly dependent on the nervous system and vice versa. Nervous experiences, overwork lead to an increase in the level of the stress hormone cortisol. It is secreted in the adrenal medulla along with adrenaline. These hormones in combination can cause persistent or intermittent hypertension with periods of blood pressure normalization. This is expressed in the fact that the pressure jumps - then high, then low at different times of the day.

For example, taking hormonal contraceptives can provoke the fact that the pressure jumps - then high, then low.

Changes in weather are accompanied by fluctuations in atmospheric pressure, which leads to spasm of cerebral vessels in meteorological people. In addition to pressure surges, this is accompanied by drowsiness, headaches, weakness, decreased concentration, chest pains.

Why the pressure jumps - then high, then low, we have considered above. There are several options for this pathology.

Most Common Causes of Floating Blood Pressure

The change in blood pressure can in some cases be due to sensitivity to certain foods. This is especially true for those who like very salty food.

Caffeine. Coffee causes a temporary increase in blood pressure. Three to four cups can increase it from 4 to 13 mm Hg. Those who do not regularly consume coffee may notice more significant fluctuations, regular consumers of this drink will not notice at all. Experts do not know the cause of the rise in blood pressure with caffeine, but speculate that it is due to the narrowing of blood vessels.

2 stress and medications

During stress, the arteries narrow and the heart becomes harder to work. It raises blood pressure, blood sugar, and heart rate. If you live in a situation of chronic stress, the constant stress on the heart can damage the artery and increase the risk of developing cardiovascular disease.

Medications. Certain medications, such as decongestants and anti-inflammatories, drugs can temporarily raise blood pressure.

3 diabetes and dehydration

Diabetes
damages nerves, causes frequent urination. When the body becomes dehydrated due to frequent urination and the nervous system is damaged due to excessive amounts of glucose in the blood, blood pressure regulation may not be optimal.

Dehydration
can also lead to pressure fluctuations with a sharp drop. To raise blood pressure by increasing blood volume, water retention must be restored. When dehydrated, the body loses its chemical electrolyte balance. This can lead to weakness and pressure fluctuations.

4. Deposition of calcium or cholesterol in the arteries

Calcium and cholesterol deposits in the arteries make them narrower, stiffer, not elastic, unable to relax, which causes hypertension. This phenomenon is most common among middle-aged and older people.

5.Heart problems and diseases of the nervous system

Heart problems:
such as low heart rate, heart failure, and myocardial infarction can lead to fluctuations in blood pressure.

This can lead to many disorders, including the body's inability to regulate blood pressure.

In addition, pressure surges can result in:

• fever (speeds up your heart rate);
• adrenal fatigue;
• menopause;
• a person's predisposition to fluctuating pressure;
• pregnancy;
• exposure to heat;
• age.

In some cases, experts associate fluctuations in blood pressure with a higher risk of stroke.

Elderly people are prone to morning high blood pressure

Of course, another reason, the most undesirable, may be hypertension. It is those suffering from this ailment that most painfully endure the increase in blood pressure in the morning. In this case, it is necessary to fight, as far as you can, with the factors that cause hypertension.

These include:

Overweight

Hypodynamia

Alcohol

Fatty food

Excessive salt intake

Physical and emotional overload

Differences in atmospheric pressure

Diseased kidneys

Diabetes

Atherosclerosis

Hormonal imbalance

Folk remedies can help. These plants reduce blood pressure:

1.Cranberries. You need to drink an infusion of cranberry berries and leaves or cranberry juice mixed in equal proportions with beetroot juice.

2. Kalina. Viburnum infusion helps. To prepare it, you need to grind the fruits and pour boiling water over (a glass of boiling water for two tablespoons of berries). Juice is also useful.

3.Nettle. You can use both its juice and infusion of roots and leaves.

4. Garlic and onions.

Monitor your blood pressure. Measure it often with a tonometer. Measurements must be taken on both hands. If the difference between night and morning pressures is no more than 20%, then there is no cause for concern. Think of the rise in blood pressure in the morning as a natural physiological process. If the numbers are higher, you need to take action.

A person may not always feel high blood pressure, therefore, many people for a long time do not know about the present health disorder.

If left untreated, hypertension often causes serious illness, which is detected when the first symptoms begin to appear.

The presence of hypertension can be detected in time if blood pressure indicators are regularly monitored.

The measurement is best taken throughout the day at home, in a calm environment, standing, sitting or lying on the bed. This will allow you to get more accurate data and find out if there is a threat of developing serious diseases.

How does a person's blood pressure change over the course of 24 hours?

A person does not always feel that the value of blood pressure is overestimated, not knowing about the formation of a deviation. Hypertension, if not properly treated, causes concomitant chronic diseases when symptoms become more active. Hypertension is diagnosed in the early stages if the pressure values ​​are periodically monitored. Blood pressure indicators during the day depend on many factors: body position during measurement, human condition and time of day. In order for the measurements to be as accurate as possible, they are taken at the same time of day, in a familiar environment. If the conditions are similar every day, the body's biorhythms are adjusted to them.

Blood pressure changes due to a number of factors:

• the value rises in the morning when the patient is in a horizontal position;
• the pressure drops during the day;
• in the evening the values ​​increase;
• at night, when a person is calmly resting, the pressure drops.

This explains why measurements must be taken at the same time, and it makes no sense to compare morning and evening numbers. Sometimes there is an increase in pressure when measured in a hospital or clinic. This is due to nervousness, fear or stress in front of "white coats", and as a result - the pressure rises slightly.

Causes of changes in blood pressure in a person during the day:

• excessive consumption of coffee, tea, alcohol;
• vegetative-vascular dystonia;
• overwork, stress;
• endocrine disorders;
• change of climate or weather;
• pathology of the cervical vertebrae.

Stress, fatigue, lack of sleep, anxiety and excessive workload are common causes of drops in blood pressure and hypertensive crises. This is typical for women - more emotional and unstable compared to men. Chronic stress, constant pressure surges over time provoke the development of the primary form of hypertension, which requires drug treatment.

Changes in the endocrine system also cause changes in blood pressure. Women are especially susceptible to this before menopause or menstruation. In the second part of the cycle, fluid in the body is retained, and the excessive emotionality characteristic of this period also contributes to an increase in pressure. Unstable pressure occurs due to pathological changes in the adrenal glands.

Anxiety, impatience, constipation, or standing still may affect the performance. The readings increase if a person needs to urinate or when the room is cold. The value is often distorted by electromagnetic fields, so it is not recommended to keep the phone near the tonometer. The pressure should stabilize if a person takes several deep breaths before measuring.

By the evening, the indicators grow, and at night the pressure decreases. This should be taken into account both when measuring and when taking antihypertensive drugs.

To obtain accurate blood pressure values, you must adhere to certain measurement rules. Blood pressure fluctuates during the day, and in hypertensive patients, these drops are much higher. If necessary, blood pressure is monitored in a calm state, in motion, after physical or emotional stress. Measurement of blood pressure in a calm state allows you to assess the effect on blood pressure of drugs. It is better to control blood pressure on both hands, as the values ​​differ. It is better to measure on the hand where the indicators are higher.

Conditions for obtaining the most accurate results:

• Half an hour before the measurement, do not eat, smoke, do not undergo hypothermia and do not play sports.
• Measure while sitting or lying down, having previously relaxed for 5 minutes.
• In a sitting position, lean on the back of a chair, since self-holding of the back leads to a slight increase in blood pressure.
• If a person lies, the hand is along the body, then a roller is placed under the elbow so that the hand is at the level of the thoracic region.
• When taking measurements, you cannot speak and move.
• During a series of measurements, pause between measurements for 15 seconds or longer, optimally - 1 minute.
• The cuff is slightly loosened between measurements.

How to measure blood pressure correctly

To avoid possible pathologies and serious diseases, even a healthy person needs to take measurements of his pressure once a month. However, you need to measure it correctly and it is better to prepare before this.

How to prepare for a diagnosis:

1. It is not recommended to drink strong tea and coffee. At least an hour before the study, you must refrain from this.
2. It is also recommended to refrain from sports and cigarettes.
3. If you need to take any medications, then read the instructions. Many drugs affect the cardiovascular system. It is better to discard them for the duration of the research.
4. Before starting the measurement, the patient should rest for at least 7-10 minutes.

How to measure blood pressure using a tonometer:

• Sit comfortably, relax the muscles of the arm and put it on the table. Apply a cuff on the shoulder in proportion to the position of the heart.
• Make sure that the size of the cuff fits as closely as possible to the size of your arm. You need to be especially careful if the patient is overweight.

When is the best time to take measurements:

1. First in the morning - although an hour after sleep and on an empty stomach.
2. In the evening - either before dinner, or after dinner, two hours later.

It is advisable to take measurements twice, arranging an interval between measurements of at least a minute.

The metrics are the best. If the difference is small, then you shouldn't worry - this is normal. If the values ​​are very different, then you should definitely consult a doctor.

ABPM method - daily monitoring

Daily monitoring of blood pressure allows you to identify hidden pathologies and diseases. This is the measurement of pressure indicators using automatic special equipment. Such a study lasts at least a day.

The device independently saves the indicators at a certain time. This method is used to find out which patient values ​​are optimal depending on the time of day. You can diagnose hypertension and (if any) find the right medication.

The cuff is put on the patient's shoulder and the monitor is arranged (either on the belt or on the belt). In this case, a person leads a normal life, carrying a special device with him.

How blood pressure is measured

The diagnosis of "hypertension" is made by a doctor, and he chooses the necessary treatment, but regular monitoring of blood pressure is already a task not only for medical workers, but for every person.

Today, the most common method for measuring blood pressure is based on the method proposed back in 1905 by the Russian physician NS Korotkov (see Science and Life, No. 8, 1990). It is associated with listening to sound tones. In addition, the palpation method (probing the pulse) and the method of daily monitoring (continuous pressure control) are used. The latter is very indicative and gives the most accurate picture of how blood pressure changes during the day and how it depends on different loads.

To measure blood pressure by the Korotkov method, mercury and aneroid manometers are used. The latter, as well as modern automatic and semi-automatic devices with displays, are calibrated on a mercury scale before use and periodically checked. By the way, on some of them, the upper (systolic) blood pressure is indicated by the letter "S", and the lower (diastolic) blood pressure is indicated by the letter "D". There are also automatic devices adapted to measure blood pressure at certain, established intervals (for example, this is how you can observe patients in the clinic). Portable devices have been created for daily monitoring (tracking) of blood pressure in a polyclinic.

Blood pressure fluctuates during the day: it is usually lowest during sleep and rises in the morning, reaching a maximum during the hours of daytime activity

It is important to know that in patients with arterial hypertension, nighttime blood pressure values ​​are often higher than daytime ones. Therefore, for the examination of such patients, daily monitoring of blood pressure is of great importance, the results of which make it possible to clarify the time of the most rational intake of drugs and ensure full control of the effectiveness of treatment.

The difference between the highest and lowest blood pressure values ​​during the day in healthy people, as a rule, does not exceed: for systolic - 30 mm Hg. Art., and for diastolic - 10 mm Hg. Art. With arterial hypertension, these fluctuations are more pronounced.

High blood pressure in the morning, low in the evening

Often there is such a phenomenon when blood pressure is above normal after waking up, and in the evening it goes down, coming to normal. When high blood pressure in the morning and low in the evening, the reasons for this condition may be:

• emotional stress;
• a heavy meal before bedtime;
• drinking a large amount of alcohol the night before;
• tobacco smoking;
• hormonal changes in women of mature age;
• thrombophlebitis - inflammation of the venous capillaries;
• atherosclerotic plaques in the arteries;
• diseases of the heart and blood vessels.

In old age, people often note that their blood pressure is low in the morning and high in the evening. What to do in this case? The mechanism of this leap usually lies in the imbalance of the regulatory system. The above factors affect the hormonal regulation of metabolism and water-electrolyte metabolism, thus causing an increase in pressure.

In case of fluctuations in blood pressure during the day, any specialist will advise you to adhere to a sleep regimen, eat right, and do moderate exercise whenever possible.

In more serious cases, a doctor may prescribe drug therapy aimed at treating pathologies of the cardiovascular, urinary, endocrine, and nervous systems. Any appointment should be carried out after the examination: you need to do the appropriate biochemical analyzes and diagnostic studies. You can not self-medicate!

• exclusion from the diet of fatty meats;
• foods rich in dietary fiber and vitamins should prevail;
• fractional meals, in small portions;
• reducing the consumption of salt and spices;
• the use of tonic drinks and alcoholic products should be minimized;
• make freshly squeezed juices;
• steam cooking.

For useful information on how to normalize blood pressure, see the following video:

You still feel that hypertension is difficult to cure.

Judging by the fact that you are reading these lines now, the victory in the fight against pressure is not yet on your side ...

The consequences of high blood pressure are known to everyone: they are irreversible damage to various organs (heart, brain, kidneys, blood vessels, fundus). At later stages, coordination is impaired, weakness appears in the arms and legs, vision deteriorates, memory and intelligence are significantly reduced, and a stroke can be triggered.

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VseDavlenie.ru »Diagnostics and treatment of pressure» All about pressure surges

Other physiological changes in pressure

Physiological abnormalities in blood pressure remain unnoticed by many. But there are times when unstable pressure is monitored, and the change in indicators does not correspond to the norm. Then we can assume the relationship between deviations and the following states of the body:

We can talk about the development of pathology if a person also has endocrine disorders.

• Stressful situations, anxiety, emotional stress, lack of sleep are common reasons that can change blood pressure.
• Development of a pathological condition:
  • disruption of the endocrine glands;
  • pathology of the autonomic nervous system;
  • cardiovascular diseases.
• Age features and pregnancy.

To prevent and prevent the development of serious pathologies, blood pressure should be measured once or twice a year. A study may show certain deviations: an increase in pressure, a decrease or constant jumps. Such conditions are dangerous, so as not to start more complex pathological processes, you should immediately consult a doctor.

Arterial hypertension

An increase in blood pressure (140/90 mm Hg and above) is observed with hypertension, or, as it is commonly called abroad, essential hypertension (95% of all cases), when the cause of the disease cannot be established, and with so-called symptomatic hypertension (only 5%), developing as a result of pathological changes in a number of organs and tissues: with kidney disease, endocrine diseases, congenital narrowing or atherosclerosis of the aorta and other large vessels. Arterial hypertension is called a silent and mysterious killer for a reason. In half of the cases, the disease is asymptomatic for a long time, that is, a person feels completely healthy and does not suspect that an insidious disease is already eroding his body. And suddenly, like a bolt from the blue, serious complications develop: for example, stroke, myocardial infarction, retinal detachment. Many of those who survived the vascular catastrophe remain disabled, for whom life is immediately divided into two parts: “before” and “after”.

Recently I had to hear from a patient a striking phrase: "Hypertension is not a disease, blood pressure is increased in 90% of people." The figure is, of course, greatly exaggerated and based on rumors. As for the opinion that hypertension is not a disease, this is a harmful and dangerous delusion. It is these patients who, what is especially depressing, the vast majority do not take antihypertensive drugs or are not treated systematically and do not control blood pressure, frivolously risking their health and even their lives.

In Russia, 42.5 million people currently have elevated blood pressure, that is, 40% of the population. Moreover, at the same time, according to a representative national sample of the population of Russia aged 15 years and older, 37.1% of men and 58.9% of women knew about the presence of arterial hypertension, and only 5.7% of patients received adequate antihypertensive therapy. men and 17.5% women.

So in our country there is a lot of work to be done to prevent cardiovascular accidents - to achieve control over arterial hypertension. The target program “Prevention and treatment of arterial hypertension in the Russian Federation,” which is currently being carried out, is aimed at solving this problem.

The text of the work is placed without images and formulas.
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Introduction

Main part

Theoretical part

Practical part

Study of the problem of the dependence of blood pressure on atmospheric by the method of social survey (Internet survey)

Conclusion

Bibliography

Introduction:

The actions of atmospheric pressure and atmospheric phenomena (thunderstorm, hot and dry winds, fog, snowfall, etc.), according to various scientists, affect the well-being of about 75% of people. According to various sources, this figure fluctuates somewhat, but all authors agree with the very fact of the influence of atmospheric phenomena on human well-being. This is confirmed by the life experience of any of us. The concept of "meteorological sensitivity" includes the influence of several factors on human health in general. The very value of atmospheric pressure (or its change) is only one of the factors affecting the well-being in general. And we want to focus on the specific influence of the atmospheric pressure (its changes) on the value of the arterial blood pressure. At the same time, we tried to concretize the problem and dwell on the influence of changes in atmospheric pressure on the value of blood pressure in adolescents.

During adolescence, health problems often occur that are temporary in nature, that is, they disappear with age. This is due to the fact that during the period of rapid growth and development of the body, many organs and functions of a person develop at different rates. Among other things, it is also influenced by the fact that it is in adolescence that serious hormonal changes take place in the body.

In most cases, it is impossible to avoid changes in blood pressure in such a situation. But it seems to us that if adolescents know what exactly these drops may be associated with, then it will be easier for them to perceive and experience it. Many of our friends and classmates often go to the doctor with complaints of high or low blood pressure. But they do not have any associated chronic diseases.

Based on the foregoing, we believe that the study of this problem is important, necessary and interesting.

Purpose of the study

Research objectives:

evaluate the opinion of respondents on this issue

to find out the opinion of medical workers who are directly related to working with adolescents on this problem

to experimentally reveal the dependence of blood pressure on atmospheric pressure in adolescents

Research hypothesis:

Research methods:

study of literary sources and Internet resources on the topic of research

method of direct measurement of atmospheric and blood pressure

For 10 consecutive days, we measured blood pressure in a group of subjects of 13 and 14 years old (using the help of classmates). In parallel, we measured atmospheric pressure with a barometer.

method of analyzing and comparing the obtained measurement results

Based on the results of direct measurements, we built a series of graphical dependencies that clearly demonstrate the presence or absence of a relationship between pressures.

social survey method (internet survey)

Taking advantage of the possibilities of the Internet, we invited adolescents who were completely unfamiliar to us to answer several questions on the topic of our research. We believe that it is the Internet that makes it possible to interview a large number of people in a short time and thereby make statistical data the most accurate.

interviewing method

The topic of our research directly concerns human health, therefore the opinion of medical workers on the topic of our research seems to us the most authoritative.

Separately, I would like to note that the urgency of this problem, we ourselves began to understand more and more in the process of working on the study. Here are the main points of the relevance of the problem of the dependence of adolescent blood pressure (and its changes) on the value of atmospheric pressure:

it affects human health

the term "meteosensitivity" implies dependence on a range of atmospheric changes without specifically identifying atmospheric pressure

we ourselves are adolescents and this problem concerns us personally and our friends

it was interesting for us to study this problem, we learned a lot of new and interesting things for ourselves

II. Main part

II.I Theoretical part

Pressure: basic concepts

Pressure (P) is a physical quantity that characterizes the state of a continuous medium and is numerically equal to the force acting per unit surface area perpendicular to this surface.

SI pressure is measured in pascals: [p] = Pa

In medicine, meteorology and many other areas of human activity, pressure is measured in millimeters of mercury (mm Hg)

The following pressure units are also used:

Bar , T technical atmosphere, physical atmosphere , meter of water column , inch of mercury , pound-force per square inch .

Measurement of pressure of gases and liquids is performed using manometers, differential pressure gauges, vacuum gauges, atmospheric pressure - barometers, blood pressure - tonometers.

Atmosphere pressure:

The atmosphere is the Earth's air envelope. Air is a mixture of gases, the main of which are nitrogen and oxygen. The Earth's atmosphere stretches for several thousand kilometers and its density decreases with distance from the Earth's surface.

The mass of the modern atmosphere is approximately one millionth of the mass of the Earth. With altitude, the density and pressure of the atmosphere sharply decrease, and the temperature changes unevenly and complexly, including due to the influence of solar activity on the atmosphere. and magnetic storms. The change in temperature within the boundaries of the atmosphere at different altitudes is explained by the unequal absorption of solar energy by gases. The most intense thermal processes occur in the troposphere, and the atmosphere is heated from below, from the surface of the ocean and land.

It should be noted that the atmosphere is of great ecological importance. It protects all living organisms of the Earth from the destructive effects of cosmic radiation and meteorite impacts, regulates seasonal temperature fluctuations, balances and evens out diurnal ones. If the atmosphere did not exist, then the fluctuation of the daily temperature on Earth would reach ± ​​200 ° C.

We are used to perceiving the presence of the atmosphere as a fact, but atmospheric air only seems to us weightless. In fact, it has weight, which can be shown by simple calculations:

Let's calculate the weight of air in a volume of 1 m3 near the Earth's surface:

Р = m.g - the formula for calculating the body weight of a known mass

m = ρ.V, where ρ = 1.29 kg / m3 is the air density near the Earth's surface

Weight of 1 m3 of air:

P = 1.29kg / m3.1m3.9.8N / kg ≈ 13N

So, the weight of one cubic meter of air is about 13 N. The air presses on the Earth with its weight, therefore, it exerts pressure. This pressure is called atmospheric pressure.

Atmospheric pressure - the pressure of the atmosphere on all objects in it and the Earth's surface. Atmospheric pressure is created by the gravitational attraction of air to the Earth.

Normal atmospheric pressure is called a pressure of 760 mm Hg at sea level at a temperature of 15 0 C (or 101 325 Pa.) It is customary for surface calculations to consider a normal atmospheric pressure of 100 kPa.

When broadcasting the weather on the radio, the announcers at the end usually report: atmospheric pressure is 760 mm Hg (or 749, or 754 ...). But how many people understand what this means, and where do forecasters get this data?

Measure the atmospheric pressure in order to be more likely to predict possible changes in the weather. There is a direct link between pressure changes and weather changes. An increase or decrease in atmospheric pressure can, with some probability, be a sign of a change in the weather. A decrease in pressure is followed by cloudy, rainy weather, and an increase is followed by dry weather, with a strong cooling in winter.

Blood pressure

Blood pressure is the pressure that blood exerts on the walls of blood vessels, or, in other words, the excess of fluid pressure in the circulatory system over atmospheric pressure. The most commonly measured blood pressure; besides it, the following types of blood pressure are distinguished: intracardiac, capillary, venous.

Blood pressure is one of the most important parameters characterizing the work of the circulatory system. Blood pressure is determined by the volume of blood pumped per unit of time by the heart and the resistance of the vascular bed.

The upper number, systolic blood pressure, shows the pressure in the arteries as the heart contracts and pushes blood into the arteries. The lower number is diastolic pressure, which shows the pressure in the arteries when the heart muscle relaxes. Diastolic pressure is the minimum pressure in the arteries. As the blood moves along the vascular bed, the amplitude of blood pressure fluctuations decreases, venous and capillary pressure little depends on the phase of the cardiac cycle.

Typical arterial blood pressure of a healthy person (systolic / diastolic) = 120/80 mm Hg. Art., pressure in large veins by several mm. rt. Art. below zero (below atmospheric). The difference between systolic blood pressure and diastolic (pulse pressure) is normally 30-60 mm Hg. Art.

The easiest way to measure blood pressure. It can be measured using a sphygmomanometer (tonometer) device. This is what is usually meant by blood pressure.

Modern digital semiautomatic tonometers make it possible to limit ourselves only to a set of pressure (up to a sound signal), further pressure relief, registration of systolic and diastolic pressure, the device conducts itself.

Influence of various factors on blood pressure indicators

Blood pressure depends on many factors:

time of day,

the psychological state of a person (with stress, the pressure rises),

taking various stimulating substances (coffee, tea, amphetamines) or medicines that increase blood pressure.

from the frequency of contractions of the heart, which drives blood through the vessels,

on the quality of the walls of blood vessels (their elasticity), which provide blood resistance,

on the volume of circulating blood and its viscosity,

the age of the person

Influence of the value of atmospheric pressure on the value of blood pressure in human blood:

The effects of atmospheric pressure and atmospheric phenomena (thunderstorm, hot and dry winds, fogs, snowfall, etc.), according to various scientists, affect the well-being of about 75% of the population. But the very value of atmospheric pressure (or its change) is only one of the factors affecting well-being in general. The concept of "meteorological sensitivity" includes the influence of several factors on human health in general. And we want to focus on the specific influence of the atmospheric pressure (its changes) on the value of the arterial blood pressure.

Meteosensitivity

Meteosensitivity is the body's response to the impact of meteorological (weather) factors. Meteosensitivity is quite widespread and occurs under any, but more often unusual climatic conditions for a given person. About a third of the inhabitants of temperate latitudes "feel" the weather. A feature of these reactions is that they occur in a significant number of people synchronously with changes in meteorological conditions or somewhat ahead of them.

Meteosensitivity has long caused surprise and even fear of a person before an incomprehensible phenomenon of nature. People who sense the weather were called "living barometers", "petrels", "weather prophets". Already in ancient times, doctors guessed about the effect of weather on the body. For a healthy person, meteorological fluctuations, as a rule, are not dangerous. Nevertheless, in people who do not feel the weather, reactions to it still appear, although sometimes they are not realized. They must be taken into account, for example, by transport drivers. With a sharp change in weather conditions, it becomes more difficult for them to concentrate. Hence, the number of accidents can increase. As a result of illness (flu, tonsillitis, pneumonia, joint diseases, etc.) or overwork, the body's resistance and reserves are reduced. That is why meteosensitivity is observed in 35-70% of patients with various diseases. So, every second patient with diseases of the cardiovascular system feels the weather. Significant atmospheric changes can cause overstrain and disruption of adaptation mechanisms. Then the oscillatory processes in the body - biological rhythms are distorted, become chaotic. The physiological (asymptomatic) weather response can be compared to a calm lake, along which waves from a light breeze travel. A pathological (painful) weather reaction is a kind of vegetative "storm" in the body. Dysregulation of the autonomic nervous system contributes to its development. The number of autonomic disorders has been increasing recently, which is associated with the action of unfavorable factors of modern civilization: stress, haste, physical inactivity, overeating and malnutrition, etc. In addition, the functional state of the nervous system is far from the same for different people. This determines the fact that often with the same diseases, diametrically opposite weather reactions are noted: favorable and unfavorable. More often meteosensitivity is observed in persons with a weak (melancholic) and strong unbalanced (choleric) type of the nervous system. In people of a strong balanced type (sanguine), meteosensitivity is manifested only when the body is weakened. The body is influenced both by the weather in general and by its individual components.

Fluctuations in barometric (atmospheric) pressure act in two ways:

reduce blood oxygen saturation (effect of barometric "pits")

mechanically irritate the nerve endings (receptors) of the pleura (the mucous membrane lining the pleural cavity), the peritoneum (lining the abdominal cavity), the synovial membrane of the joints, as well as vascular receptors.

Under normal conditions on the surface of the earth, annual fluctuations in atmospheric air do not exceed 20-30 mm, and daily fluctuations are 4-5 mm. Healthy people tolerate them easily and unnoticed. Some patients are very sensitive to even such minor changes in blood pressure. So, with a decrease in pressure in persons suffering from rheumatism, pains appear in the affected joints, in patients with hypertension, the state of health worsens, attacks of angina pectoris are observed. In people with increased nervous excitability, sudden changes in pressure cause the appearance of a feeling of fear, deterioration of mood and sleep. Changes in atmospheric pressure, especially abrupt ones, negatively affect the circulatory system, vascular tone, and blood pressure.

The well-being of a person who has lived for a long time in a certain area is normal, i.e. the characteristic pressure should not cause any particular deterioration in well-being.

Staying in conditions of high atmospheric pressure is almost no different from normal conditions. Only at very high blood pressure is there a slight decrease in heart rate and a decrease in minimum blood pressure. Breathing becomes more rare, but deeper. Hearing and smell are slightly reduced, the voice becomes muffled, there is a feeling of a slightly numb skin, dryness of mucous membranes, etc. However, all these phenomena are relatively easily tolerated.

More unfavorable phenomena are observed during the period of atmospheric pressure change - an increase (compression) and especially its decrease (decompression) to normal. The slower the pressure change, the better and without adverse consequences the human body adapts to it.

With a reduced atmospheric pressure, there is an increase and deepening of breathing, an increase in heart rate (their strength is weaker), a slight drop in blood pressure, and changes in the blood are also observed in the form of an increase in the number of red blood cells. Oxygen starvation is the cornerstone of the adverse effect of low atmospheric pressure on the body. It is due to the fact that with a decrease in atmospheric pressure, the partial pressure of oxygen also decreases.

The mechanism of the relationship between atmospheric and blood pressure:

Atmospheric air is a mixture of gases, the pressure of each of which contributes to the value of the total atmospheric pressure. This contribution of separately taken oxygen is the partial pressure of this gas. Consequently, with a decrease in atmospheric pressure, the partial pressure of oxygen also decreases, which leads to oxygen starvation and with the normal functioning of the respiratory and circulatory organs, a smaller amount of oxygen enters the body.

According to medical statistics, a healthy person feels most comfortable with an atmospheric pressure of 760 mm. rt. Art.

II.II Practical part

II.II.I Investigation of the problem of the dependence of blood pressure on the atmospheric method social survey (internet survey)

using the method of social questioning (Internet survey) to find out the opinion of the target audience about the possibility of a person's blood (arterial) pressure being dependent on atmospheric pressure.

Target audience of the social survey: respondents from 10 to 20 years old.

Questions asked:

		Answer options
	Your age?		10 to 15 years old	15 to 20 years old		Over 20 years old

Results analysis method:

The questionnaires of the respondents who chose the following options for answering the questions were excluded and were not subject to analysis:

		Answer options
	Are you ready to help us with our research?
	Your age?					Over 20 years old
	Have you ever experienced a drop or increase in blood pressure?
	Are you interested in the value of the atmospheric pressure indicated in the weather forecast? (or measure yourself)
	Do you think changes in your blood pressure are related to changes in atmospheric pressure?

As a result, the questionnaires of respondents who are ready to help us, who are adolescents (we slightly expanded the age range), who have problems with blood pressure and who have an idea of ​​atmospheric pressure, were accepted for processing. To simplify the data processing process, we stopped the Internet survey on the hundredth questionnaire that meets the above requirements.

Yes - 65% No - 15% Don't know - 20%

Conclusion: most adolescents who have problems with blood pressure tend to associate this with changes in atmospheric pressure.

Comments: Adolescents do not have a special medical education, do not measure blood pressure every day, in addition, they may have other health problems that affect the value of blood pressure. Therefore, the results of a social survey express only the opinion of the audience on this issue, and not a direct relationship between the phenomena under consideration.

Investigation of the problem of blood pressure dependence on atmospheric pressure by interviewing

The task of this stage of the study: to find out the opinion of medical workers who are directly related to working with adolescents on this problem.

Interview with school paramedic Kostyakova Svetlana Valerievna:

Question: Please tell me how often teenagers come to you with a problem of high or low blood pressure?

Answer: very often in the process of medical prophylactic examination, we reveal a number of problems directly related to deviations from the normal value of blood pressure.

Question: what do you think, with what it can be connected?

Answer: it seems to me that there are several main reasons. This is, firstly, our changeable northern weather. The fragile body of a teenager simply does not have time to react mobilely and correctly and quickly adapt to such changes. According to statistics, adolescents in regions with a more stable climate are much less affected by such deviations.

And secondly, this is a heavy workload of children: school, circles, sections, tutors.In big cities, this problem is even more acute ..

Question: Do you believe that many healthy people are weather dependent?

Answer: you know, now some St. Petersburg medical centers specialize in correcting meteorological dependence. Whole methods have been developed, including herbal medicine, remedial gymnastics, breathing exercises and much more. But these clinics mainly specialize in the treatment of middle-aged and elderly people, or people with chronic pathologies in this area. And in adolescents, meteorological dependence can be a temporary, age-related problem. But if a teenager is sure that changes in the weather affect his condition, no one bothers him to be interested in the weather forecast in advance and based on this make his plans for the coming days. Nature still has many secrets and questions to which there are no concrete answers yet.

Investigation of the problem of blood pressure dependence on atmospheric by experimental method.

The task of this stage of the study: experimentally, by means of direct measurements, to reveal the dependence of blood pressure on atmospheric pressure in adolescents.

Experiment progress: for 10 days, blood pressure was measured in eight subjects, 13 and 14 years old. In parallel, we measured the atmospheric pressure with a barometer, comparing the readings with the weather forecast data for these days. The difference between the experimental values ​​of atmospheric pressure and the data of the meteorological forecast turned out to be insignificant. Therefore, for comparison and analysis, we used the data obtained independently during the experiment.

Data processing technique: we entered the data of direct measurements into the table (see below). In the course of the comparative analysis, we came to the conclusion that there is a need to make additional calculations based on the results of direct measurements. The data was also entered into the table (see below). The following graphs turned out to be more illustrative, which allowed us to draw a conclusion that practically confirms our hypothesis.

Table No. 1, data of direct measurements of pressure (mm Hg)

	Atmospheric pressure value	Blood pressure value
		Tanina Alina	Maleeva Tatiana	Agafonov Igor	Grebeneva Irina	Sazonov Kirill	Yarulin Maxim	Rooster Alena	Gukkina Nadezhda

Graph No. 1: value of atmospheric pressure

Graph No. 2: the value of blood pressure of two subjects

The experimental data did not reveal a direct relationship between the pressure values.

Based on the fact that when comparing the data of direct measurements, the conclusion is not entirely obvious, we assumed that the relationship may exist not so much between the absolute values ​​of pressures as between changes these values.

Table No. 2

Difference modulus between the current pressure value and the next

in mm Hg (∆ p)

	atmospheric

Graph No. 3: change in atmospheric pressure

Schedule No. 4

Comparison of changes in atmospheric and blood pressure

Diagram # 1: Comparison of changes in atmospheric and blood pressure

Conclusions from this part of the study:

Based on the analysis of experimental data, we can assert that CHANGES in atmospheric pressure (in one direction or another) lead to CHANGES in blood pressure, which is clearly demonstrated by graph No. 2. That is, we can assert that blood pressure depends from atmospheric, more preciselychanges atmospheric pressure lead tochange blood pressure in adolescents.

Conclusion

The study of the link between human health and atmospheric phenomena has a long history, in which facts are mixed with legends. Already the father of medicine, Hippocrates, in his famous treatise "On Airs, Waters and Localities" outlined the essence of the influence of weather on a person. Now the study of this problem is mainly engaged in medical centers specializing in the treatment of hypotension and hypertension. For our study, we chose one of the aspects of meteosensitivity - the effect of atmospheric pressure on the well-being of adolescents.

The aim of our study was: to study the dependence of changes in the value of blood pressure in adolescents from changes in the value of atmospheric pressure.

We assumed that such a dependence exists, therefore we put forward a hypothesis about the presence of this dependence.

Research hypothesis: Based on the information we received from literary and Internet sources, we assume that blood pressure in adolescents depends on atmospheric pressure.

We approached the study of this problem from several points of view. We were interested in the question of whether this problem worries our peers. To address this issue, we conducted an Internet survey among a large group of adolescents, the result turned out to be very clear - 65% of respondents are inclined to consider our hypothesis as correct. Then we were interested in the question of what medical workers who are directly related to working with adolescents think about the effect of atmospheric pressure on the health of schoolchildren. From an interview with a teenage doctor and a school paramedic, we received a lot of useful and indicative information, which also practically confirms our hypothesis. Further, it seems appropriate to us to quote the famous philosopher, inventor and painter Leonardo da Vinci. He argued that:

“The interpreter of nature's tricks is experience; he never deceives.

Those who study science do not turn to nature, but to authors, cannot be considered the sons of nature; I would say that they are only her grandchildren. "

To paraphrase the great genius, we want to say that only experimental data can directly confirm or refute the hypothesis put forward. Therefore, the practical part of our work is an experiment comparing the values ​​of the arterial and atmospheric pressure of adolescents for 10 days and further analysis of the data obtained.

We believe that we have completed the tasks set and present to your attention particular conclusions on each of the tasks set, as well as a general conclusion corresponding to the set goal of the work:

General conclusion:

the relationship between the value of atmospheric pressure and the value of blood pressure in adolescents exists. The essence of this relationship lies in the fact that changes in atmospheric pressure in most cases lead to changes in blood (systolic) pressure in adolescents.

We have considered only a small aspect of the general problem of the influence of atmospheric phenomena on human health. In the process of research work, we received a lot of useful information, and realized that the problem itself is much broader than the specific topic of our research. If we have such an opportunity, we will definitely continue to study this issue and in the future we will consider other aspects of the influence of atmospheric phenomena on human health in general and adolescents in particular.

List of used literature and Internet resources:

Kuznetsov B.G. Paths of Physical Thought. - M .: Nauka, 1968, 350 p.

A. V. Peryshkin Physics 7. - M .: Bustard, 2008, 193 p.

Peryshkin A. V, Physics 7. - M: Bustard, 2014, 224 pp.

Ryzhenkov A.P. Physics, man, environment. - M .: Education, 2001, 35 p.

Simanov Yu. G. Live barometers. - M .: Banner, 1986, 128 p.

Encyclopedia of the student: 4000 fascinating facts. - M .: Makhaon, 2003, 350 p.

http // ru.wikipedia.org

http / www.d-med.org

Attention! The administration of the site rosuchebnik.ru is not responsible for the content of methodological developments, as well as for the compliance of the development of the Federal State Educational Standard.

• Participant: Vertushkin Ivan Alexandrovich
• Head: Elena Vinogradova
Topic: "Atmospheric pressure"

Introduction

It's raining outside the window today. After the rain, the air temperature decreased, the humidity increased and the atmospheric pressure decreased. Atmospheric pressure is one of the main factors determining the state of weather and climate, therefore knowledge of atmospheric pressure is essential in weather forecasting. The ability to measure atmospheric pressure is of great practical importance. And it can be measured with special barometer instruments. In liquid barometers, as the weather changes, the liquid column goes down or up.

Knowledge about atmospheric pressure is necessary in medicine, in technological processes, human life and all living organisms. There is a direct link between changes in atmospheric pressure and changes in weather. An increase or decrease in atmospheric pressure can be a sign of a change in the weather and affect a person's well-being.

Description of three interrelated physical phenomena from everyday life:

• The relationship between weather and atmospheric pressure.
• The phenomena underlying the operation of instruments for measuring atmospheric pressure.

Relevance of work

The relevance of the chosen topic lies in the fact that at all times people, thanks to their observations of the behavior of animals, could predict weather changes, natural disasters, and avoid human casualties.

The influence of atmospheric pressure on our body is inevitable, abrupt changes in atmospheric pressure affect the well-being of a person, meteorological people are especially affected. Of course, we cannot reduce the effect of atmospheric pressure on human health, but we can help our own body. Correctly organizing your day, distributing time between work and rest can be helped by the ability to measure atmospheric pressure, knowledge of folk signs, and the use of home-made devices.

Purpose of work: find out what role atmospheric pressure plays in a person's daily life.

Tasks:

• Examine the history of atmospheric pressure measurements.
• Determine if there is a relationship between weather and atmospheric pressure.
• To study the types of instruments designed to measure atmospheric pressure, made by man.
• Study the physical phenomena underlying the operation of instruments for measuring atmospheric pressure.
• The dependence of the liquid pressure on the height of the liquid column in liquid barometers.

Research methods

• Analysis of the literature.
• Generalization of the information received.
• Observations.

Field of study: Atmosphere pressure

Hypothesis: atmospheric pressure is essential for humans .

Significance of work: the material of this work can be used in the classroom and in extracurricular activities, in the life of my classmates, students of our school, all lovers of nature research.

Work plan

I. Theoretical part (collection of information):

1. Review and analysis of the literature.
2. Internet resources.

II. Practical part:

• observation;
• collection of weather information.

III. Final part:

1. Conclusions.
2. Work presentation.

History of atmospheric pressure measurement

We live at the bottom of a vast air ocean called the atmosphere. All changes that occur in the atmosphere will certainly have an impact on a person, on his health, ways of life, because man is an integral part of nature. Each of the factors that determine the weather: atmospheric pressure, temperature, humidity, ozone and oxygen content in the air, radioactivity, magnetic storms, etc. has a direct or indirect effect on human well-being and health. Let's dwell on atmospheric pressure.

Atmosphere pressure- this is the pressure of the atmosphere on all objects in it and the Earth's surface.

In 1640, the Grand Duke of Tuscany decided to arrange a fountain on the terrace of his palace and ordered for this to bring water from a nearby lake using a suction pump. The invited Florentine craftsmen said it was impossible because the water had to be sucked to a height of over 32 feet (over 10 meters). And why water is not sucked up to such a height, they could not explain. The Duke asked the great Italian scientist Galileo Galilei to understand. Although the scientist was already old and sick and could not engage in experiments, he nevertheless suggested that the solution to the problem lies in the field of determining the weight of air and its pressure on the water surface of the lake. Galileo's student Evangelista Torricelli took up the solution to this issue. To test the hypothesis of his teacher, he conducted his famous experiment. He filled a glass tube 1 m long, sealed at one end, completely with mercury, and tightly closing the open end of the tube, turned it over with this end into a cup with mercury. Some of the mercury spilled out of the tube, some remained. An airless space formed above the mercury. The atmosphere presses on the mercury in the cup, the mercury in the tube also presses on the mercury in the cup, since equilibrium has been established, these pressures are equal. Calculating the pressure of mercury in a tube means calculating the pressure of the atmosphere. If the atmospheric pressure rises or falls, then the column of mercury in the tube rises or falls, respectively. This is how the unit for measuring atmospheric pressure - mm - appeared. rt. Art. - millimeter of mercury. Observing the level of mercury in the tube, Torricelli noticed that the level is changing, which means that it is not constant and depends on changes in the weather. If the pressure rises, the weather will be good: cold in winter, hot in summer. If the pressure drops sharply, then cloudiness and moisture saturation are expected. The Torricelli tube with an attached ruler is the first device for measuring atmospheric pressure - the mercury barometer. (Annex 1)

Other scientists also created barometers: Robert Hooke, Robert Boyle, Emile Marriott. The water barometers were designed by the French scientist Blaise Pascal and the German burgomaster of the city of Magdeburg Otto von Guericke. The height of such a barometer was more than 10 meters.

To measure pressure, different units are used: mm of mercury, physical atmospheres, in the SI system - Pascals.

The relationship between weather and atmospheric pressure

In Jules Verne's novel The Fifteen-Year-Old Captain, I was interested in the description of how to understand the readings of the barometer.

“Captain Gul, a good meteorologist, taught him to understand the readings of the barometer. We will briefly tell you how to use this wonderful device.

1. When, after a long period of good weather, the barometer begins to fall sharply and continuously, this is a sure sign of rain. However, if the weather was fine for a very long time, then the mercury column can go down for two or three days, and only after that any noticeable changes will occur in the atmosphere. In such cases, the longer the time elapsed between the beginning of the fall of the mercury column and the beginning of the rains, the longer the rainy weather will be.
2. On the contrary, if during a long period of rains the barometer starts to rise slowly but continuously, one can confidently predict the onset of good weather. And good weather will last the longer, the more time has passed between the beginning of the rise of the mercury column and the first clear day.
3. In both cases, the change in weather that occurred immediately after the rise or fall of the mercury column is retained for a very short time.
4. If the barometer slowly but continuously rises for two or three days or longer, it portends good weather, at least all these days it rained without ceasing, and vice versa. But if the barometer rises slowly on rainy days, and immediately begins to fall with the onset of good weather, the good weather will not last long, and vice versa
5. In spring and autumn, a sharp drop in the barometer foreshadows windy weather. In summer, in extreme heat, it predicts a thunderstorm. In winter, especially after prolonged frosts, the rapid fall of the mercury column indicates an impending change in wind direction, accompanied by thaw and rain. On the contrary, an increase in the mercury table ba during prolonged frosts portends snowfall.
6. Frequent fluctuations in the level of the mercury column, now rising, now falling, should in no case be considered as a sign of the approach of a long one; period of dry or rainy weather. Only a gradual and slow fall or rise in the mercury column foreshadows the onset of a long period of steady weather.
7. When at the end of autumn, after a long period of winds and rains, the barometer begins to rise, this foreshadows the north wind in the onset of frost.

Here are the general conclusions that can be drawn from the readings of this valuable instrument. Dick Sand was very good at understanding barometer predictions and was convinced many times how correct they were. Every day he consulted his barometer so as not to be caught off guard by the changing weather. "

I made observations of changes in weather and atmospheric pressure. And I was convinced that this dependence exists.

date	Temperature,° C	Precipitation,	Atmospheric pressure, mm Hg	Cloudiness
				Mainly cloudy
				Mainly cloudy
				Mainly cloudy
				Mainly cloudy
				Mainly cloudy
				Mainly cloudy
				Mainly cloudy

Devices for measuring atmospheric pressure

For scientific and everyday purposes, you need to be able to measure atmospheric pressure. There are special devices for this - barometers... Normal atmospheric pressure is the pressure at sea level at 15 ° C. It is equal to 760 mm Hg. Art. We know that when the altitude changes by 12 meters, the atmospheric pressure changes by 1 mm Hg. Art. Moreover, with an increase in altitude, atmospheric pressure decreases, and with a decrease, it rises.

The modern barometer is made liquid-free. It's called aneroid barometer. Metal barometers are less accurate, but less cumbersome and fragile.

- a very sensitive device. For example, going up to the last floor of a nine-story building, due to the difference in atmospheric pressure at different heights, we will find a decrease in atmospheric pressure by 2-3 mm Hg. Art.




The barometer can be used to determine the flight altitude of the aircraft. Such a barometer is called a barometric altimeter or altimeter... The idea of ​​Pascal's experiment formed the basis for the design of the altimeter. It determines the height of rise above sea level from the change in atmospheric pressure.

When observing the weather in meteorology, if it is necessary to register fluctuations in atmospheric pressure over a certain period of time, they use a recorder - barographer.




(Storm Glass) storm- "storm" and glass- "glass") is a chemical or crystalline barometer consisting of a glass flask or ampoule filled with an alcohol solution in which camphor, ammonia and potassium nitrate are dissolved in certain proportions.




This chemical barometer was actively used during his sea voyages by the English hydrographer and meteorologist, Vice Admiral Robert Fitzroy, who carefully described the behavior of the barometer, this description is still used today. Therefore, the stormglass is also called the "Fitzroy Barometer". Between 1831 and 1836 Fitzroy headed an oceanographic expedition aboard the Beagle, in which Charles Darwin took part.

The barometer works as follows. The flask is hermetically sealed, but, nevertheless, the birth and disappearance of crystals constantly occurs in it. Depending on the upcoming weather changes, crystals of various shapes are formed in the liquid. Stormglass is so sensitive that it can predict a sharp change in the weather 10 minutes before. The principle of operation has not received a complete scientific explanation. The barometer works better by being near the window, especially in reinforced concrete houses, probably in this case the barometer is not so much shielded.




Baroscope- a device for monitoring changes in atmospheric pressure. You can make a baroscope with your own hands. To make a baroscope, the following equipment is required: Glass jar with a volume of 0.5 liters.




1. A piece of film from a balloon.
2. Rubber ring.
3. Light arrow made of straw.
4. Wire for fastening the arrow.
5. Vertical scale.
6. The body of the device.

Dependence of liquid pressure on the height of the liquid column in liquid barometers

With a change in atmospheric pressure in liquid barometers, the height of the liquid column (water or mercury) changes: with a decrease in pressure, it decreases, with an increase, it increases. This means that there is a dependence of the height of the liquid column on atmospheric pressure. But the liquid itself presses on the bottom and walls of the vessel.

The French scientist B. Pascal in the middle of the 17th century empirically established a law called Pascal's law:

The pressure in a liquid or gas is transmitted in all directions in the same way and does not depend on the orientation of the site on which it acts.

To illustrate Pascal's law, the figure shows a small rectangular prism immersed in a liquid. If we assume that the density of the prism material is equal to the density of the liquid, then the prism should be in the liquid in a state of indifferent equilibrium. This means that the pressure forces acting on the edge of the prism must be balanced. This will only happen if the pressures, i.e., the forces acting on the unit surface area of ​​each face, are the same: p 1 = p 2 = p 3 = p.




The pressure of the liquid on the bottom or side walls of the vessel depends on the height of the liquid column. The force of pressure on the bottom of a cylindrical vessel of height h and base area S equal to the weight of a liquid column mg, where m = ρ ghS Is the mass of the liquid in the vessel, ρ is the density of the liquid. Hence p = ρ ghS / S

Same pressure at depth h in accordance with Pascal's law, the liquid also acts on the side walls of the vessel. Liquid column pressure ρ gh are called hydrostatic pressure.

In many devices that we meet in life, the laws of pressure of liquids and gases are used: communicating vessels, a water supply system, a hydraulic press, sluices, fountains, an artesian well, etc.

Conclusion

Measure the atmospheric pressure in order to be more likely to predict possible changes in the weather. There is a direct link between pressure changes and weather changes. An increase or decrease in atmospheric pressure can, with some probability, be a sign of a change in the weather. You need to know: if the pressure drops, then cloudy, rainy weather is expected, but if it rises, dry weather, with a cold snap in winter. If the pressure drops very sharply, serious bad weather is possible: storm, severe thunderstorm or storm.

Even in ancient times, doctors wrote about the effect of weather on the human body. In Tibetan medicine, there is a mention: "joint pains intensify in the rainy season and during the period of high winds." The famous alchemist, physician Paracelsus noted: "He who has studied the winds, lightning and weather knows the origin of diseases."

In order for a person to be comfortable, the atmospheric pressure must be equal to 760 mm. rt. Art. If the atmospheric pressure deviates, even by 10 mm, in one direction or another, the person does not feel comfortable and this can affect his health. Adverse events are observed during the period of atmospheric pressure changes - an increase (compression) and especially its decrease (decompression) to normal. The slower the pressure change, the better and without adverse consequences the human body adapts to it.