You need to investigate how air pressure changes. Study of natural phenomena: changes in atmospheric pressure, approaching rain. Low atmospheric pressure

Atmosphere pressure- one of the most important climatic characteristics that have an impact on humans. It contributes to the formation of cyclones and anticyclones, and provokes the development of cardiovascular diseases in people. Evidence that air has weight was obtained back in the 17th century; since then, the process of studying its vibrations has been one of the central ones for weather forecasters.

What is atmosphere

The word “atmosphere” is of Greek origin, literally translated as “steam” and “ball”. This is a gas shell around the planet, which rotates with it and forms a single cosmic body. It extends from earth's crust, penetrating the hydrosphere and ending in the exosphere, gradually flowing into interplanetary space.

The atmosphere of a planet is its most important element, ensuring the possibility of life on Earth. It contains necessary for a person oxygen, weather indicators depend on it. The boundaries of the atmosphere are very arbitrary. It is generally accepted that they begin at a distance of about 1000 kilometers from the surface of the earth and then, at a distance of another 300 kilometers, smoothly move into interplanetary space. According to theories followed by NASA, this gas shell ends at an altitude of about 100 kilometers.

It arose as a result of volcanic eruptions and the evaporation of substances in cosmic bodies falling onto the planet. Today it consists of nitrogen, oxygen, argon and other gases.

History of the discovery of atmospheric pressure

Until the 17th century, humanity did not think about whether air had mass. There was no idea what atmospheric pressure was. However, when the Duke of Tuscany decided to equip the famous Florentine gardens with fountains, his project failed miserably. The height of the water column did not exceed 10 meters, which contradicted all ideas about the laws of nature at that time. This is where the story of the discovery of atmospheric pressure begins.

Galileo’s student, the Italian physicist and mathematician Evangelista Torricelli, began studying this phenomenon. Using experiments on a heavier element, mercury, a few years later he was able to prove that air has weight. He created the first vacuum in the laboratory and developed the first barometer. Torricelli imagined a glass tube filled with mercury, in which, under the influence of pressure, such an amount of substance remained that would equalize the pressure of the atmosphere. For mercury, the column height was 760 mm. For water - 10.3 meters, this is exactly the height to which the fountains rose in the gardens of Florence. It was he who discovered for humanity what atmospheric pressure is and how it affects human life. in the tube was named the "Torricelli void" in his honor.

Why and as a result of which atmospheric pressure is created

One of the key tools of meteorology is the study of movement and movement air masses. Thanks to this, you can get an idea of ​​what causes atmospheric pressure. After it was proven that air has weight, it became clear that it, like any other body on the planet, is subject to the force of gravity. This is what causes the appearance of pressure when the atmosphere is under the influence of gravity. Atmospheric pressure can fluctuate due to differences in air mass in different areas.

Where there is more air, it is higher. In a rarefied space, a decrease in atmospheric pressure is observed. The reason for the change lies in its temperature. It is heated not by the rays of the Sun, but by the surface of the Earth. As the air heats up, it becomes lighter and rises, while the cooled air masses sink down, creating a constant, continuous movement. Each of these flows has different atmospheric pressure, which provokes the appearance of winds on the surface of our planet.

Influence on weather

Atmospheric pressure is one of the key terms in meteorology. The weather on Earth is formed due to the influence of cyclones and anticyclones, which are formed under the influence of pressure changes in the gaseous envelope of the planet. Anticyclones are characterized by high performance(up to 800 mmHg and above) and low movement speed, while cyclones are areas with lower rates and high speed. Tornadoes, hurricanes, and tornadoes are also formed due to sudden changes in atmospheric pressure - inside the tornado it rapidly drops, reaching 560 mm Hg.

Air movement causes changes in weather conditions. Winds occurring between areas with at different levels pressure, overtake cyclones and anticyclones, as a result of which atmospheric pressure is created, forming certain weather. These movements are rarely systematic and are very difficult to predict. In areas where high and low atmospheric pressure collide, climate conditions change.

Standard indicators

The average level under ideal conditions is considered to be 760 mmHg. The level of pressure changes with altitude: in lowlands or areas located below sea level, the pressure will be higher; at altitudes where the air is thin, on the contrary, its indicators decrease by 1 mm of mercury with every kilometer.

Low atmospheric pressure

It decreases with increasing altitude due to distance from the Earth's surface. In the first case, this process is explained by a decrease in the influence of gravitational forces.

Heated by the Earth, the gases that make up the air expand, their mass becomes lighter, and they rise to higher levels. The movement occurs until the neighboring air masses are less dense, then the air spreads to the sides and the pressure equalizes.

The tropics are considered traditional areas with lower atmospheric pressure. In equatorial areas there is always low pressure. However, zones with high and low levels are unevenly distributed over the Earth: in the same geographic latitude there may be areas with different levels.

Increased atmospheric pressure

Most high level on Earth it is observed at the South and North Poles. This is explained by the fact that the air above a cold surface becomes cold and dense, its mass increases, therefore, it is more strongly attracted to the surface by gravity. It descends, and the space above it is filled with warmer air masses, as a result of which atmospheric pressure is created at an increased level.

Impact on humans

Normal indicators characteristic of a person’s area of ​​residence should not have any impact on his well-being. At the same time, atmospheric pressure and life on Earth are inextricably linked. Its change - increase or decrease - can trigger the development of cardiovascular diseases in people with high blood pressure. A person may experience pain in the heart area, attacks of causeless headaches, and decreased performance.

For people suffering from respiratory diseases, anticyclones that bring high blood pressure can become dangerous. The air descends and becomes denser, and the concentration of harmful substances increases.

During fluctuations in atmospheric pressure, people's immunity and the level of leukocytes in the blood decrease, so it is not recommended to strain the body physically or intellectually on such days.

The test includes 18 tasks. You are given 1 hour 30 minutes (90 minutes) to complete the physics work.

Read the list of concepts you encountered in your physics course.

Airplane flight, ampere, melting ice, newton, electromagnetic wave, farad.

Divide these concepts into two groups according to the criteria you choose. Write down the name of each group and the concepts included in this group in the table.

Choose two true statements about physical quantities or concepts. Circle their numbers.

1. There is a box in an elevator moving downwards uniformly from rest. The modulus of the weight of the box is equal to the modulus of gravity.

2. Acceleration is a physical quantity that determines the rate of change in the speed of a body.

3. The sliding friction force depends on the area of ​​contact between the block and the surface.

4. Law universal gravity valid only for material points.

5. The binding energy of a nucleus is determined by the amount of work that needs to be done to split a nucleus into its constituent nucleons without imparting kinetic energy to them.

Show answer

The racket bends when hit by a tennis ball. Under what force does the racket bend?

Show answer

Elastic force

Read the text and fill in the missing words:

decreases

increases

does not change

Words in the answer may be repeated.

The rocket starts from the ground and, accelerating, rises to a small height above the earth's surface. During flight, the kinetic energy of the rocket __________. At the same time, the potential energy of the rocket __________. We can conclude that when a rocket launches, its total mechanical energy __________.

Show answer

increases, increases, increases

Air in a sealed vessel was placed in a vessel with water and the volume began to increase. How will the mass of air, temperature and pressure in the vessel change? For each value, determine the nature of the change and put a “V” sign in the required cell of the table.

Show answer

A bound system of elementary particles contains 8 electrons, 8 neutrons and 8 protons. Using a fragment of the Periodic Table of Elements by D.I. Mendeleev, determine which element this system is an ion or neutral atom?

Show answer

oxygen atom

The figures show the emission spectra of atomic vapors of hydrogen (1), helium (2), sodium (3), and a mixture of substances (4). Does the mixture of substances contain hydrogen, helium, sodium? Explain your answer.

Show answer

hydrogen (1), helium (2), sodium (3) contained in the mixture of substance

How long will it take a heater with a resistance of 10 ohms to produce 250 kJ of heat if electricity with a force of 10 A?

Write down the formulas and do the calculations.

Show answer

Possible answer

The formula of the Joule-Lenz law Q = I 2 Rt is written correctly and the formula for calculating time t = Q/(I 2 R) = 250,000 J/(10 2 A 2 * 10 Ohm) = 250 s is obtained.

Arrange the types of electromagnetic waves in order of increasing frequency. Write down the corresponding sequence of numbers in your answer.

1) Ɣ-radiation

2) radio waves

3) thermal radiation

Answer: _____ → _____ → _____

Show answer

Electrical voltage was measured using a voltmeter. The voltmeter scale is graduated in V. The voltage measurement error is equal to 0.5 of the voltmeter scale division. Write down the voltmeter readings in V in response, taking into account the measurement error.

Show answer

The student investigated the dependence of the length of the spring L on the mass of the loads lying in the pan of the spring scale. What value of the spring stiffness coefficient did he obtain taking into account measurement errors (\bigtriangleup m = ±1g \bigtriangleup L = ±0.2 cm)?

Write down the barometer readings in kPa in response, taking into account the measurement error.

Show answer

You need to investigate how the refractive index of light depends on the substance in which the phenomenon of light refraction is observed. The following equipment is available:

Paper;

Laser pointer;

Semicircular plates made of glass, polystyrene and rock crystal;

Protractor.

In response:

1. Describe the experimental setup.

2. Describe the procedure for conducting the study.

Show answer

1. The installation shown in the figure is used. The angle of incidence and angle of refraction are measured using a protractor.

2. Two or three experiments are carried out in which the beam laser pointer directed onto plates made of different materials (glass, polystyrene, rhinestone). The angle of incidence of the beam on the flat face of the plate is left unchanged, and the angle of refraction is measured.

3. Using the formula \frac(sin\alpha)(cos\beta)=n, the refractive indices are found and compared.

Establish a correspondence between the examples and the physical phenomena that these examples illustrate. For each example of the manifestation of physical phenomena from the first column, select the corresponding name of the physical phenomenon from the second column.

A) A skier who has slid down a hill onto a horizontal section stops.

B) A fast moving car cannot stop immediately.

PHYSICAL PHENOMENA

1) When one body slides over the surface of another, a sliding friction force arises.

2) Inertia of bodies.

3) When two bodies rub against each other, they become electrified.

4) The force of gravity is always directed towards the center of the Earth.

Show answer

Read the text and complete tasks 14 and 15.

Principle of electric air heater

Electric air heaters come in four main types: electric convectors, infrared heaters, oil heaters and fan heaters.

We will talk about only one of them - the electric convector. The convector is equipped with an electric heating element. If you specially heat the air from below, it becomes warm and moves upward. In its place comes a portion of cold air, which also heats up and rises. This phenomenon is called convection. Its essence lies in the continuous movement of air masses due to uneven heating of different layers. Air density depends on temperature: the warmer the air, the lighter it is. And according to Archimedes’ law, all less dense bodies in a liquid or gas float to the top. Therefore, warm air is always under the ceiling, and cold air is always above the floor. And this happens until all the air in the room becomes approximately the same temperature.

Install desired temperature air in the room can be controlled using the thermostat knob, setting it to the position corresponding to a certain temperature.

What happens next? For heating to occur, the electrical circuit of the convector must be closed. The thermostat should open it if the air temperature becomes too high. But when the air temperature drops, it should automatically close it again so that the air continues to heat up. To do this, the thermostat is equipped with a movable element. By turning the handle, we change the angle of inclination of this element.

The convector temperature sensor has a plate made of a material with a high coefficient of thermal expansion. The more the plate heats up, the more it bends. While the air is cold, the plate is in contact with the moving element of the thermostat. The plate changes its position depending on the degree of heating of the air. The hotter it is, the more it deviates. And it will deviate until the circuit opens. Moreover, this will happen faster if you install more low temperature.

When the circuit is open, there is no heating, so the air cools. The plate on the temperature sensor also cools and returns to its original position - to the thermostat element, the angle of which is set by the user. The circuit closes again and the air heats up.

What physical phenomenon underlies the operation of an electric convector?

Show answer

The phenomenon of warm convection

Select two correct statements from the list provided and write down the numbers under which they are indicated.

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 with the Federal State Educational Standard.

• Participant: Vertushkin Ivan Aleksandrovich
• Head: Elena Anatolyevna Vinogradova

Topic: "Atmospheric pressure"

Introduction

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

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

Description of three interrelated physical phenomena from Everyday life:

• Relationship between weather and atmospheric pressure.
• Phenomena underlying the operation of instruments for measuring atmospheric pressure.

Relevance of the work

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

The influence of atmospheric pressure on our body is inevitable; sudden changes in atmospheric pressure affect a person’s well-being, and weather-dependent people especially suffer. Of course, we cannot reduce the influence of atmospheric pressure on human health, but we can help our own body. The ability to measure atmospheric pressure, knowledge of folk signs, and the use of homemade instruments can help to properly organize your day, distribute time between work and rest.

Goal of the work: find out what role atmospheric pressure plays in human daily life.

Tasks:

• Study the history of atmospheric pressure measurement.
• Determine whether there is a connection between weather and atmospheric pressure.
• 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.
• Dependence of liquid pressure on the height of the liquid column in liquid barometers.

Research methods

• Literature analysis.
• Summarizing the information received.
• Observations.

Field of study: Atmosphere pressure

Hypothesis: Atmospheric pressure is important for humans .

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

Work plan

I. Theoretical part (information collection):

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

II. Practical part:

• observations;
• collecting weather information.

III. Final part:

1. Conclusions.
2. Presentation of work.

History of atmospheric pressure measurement

We live at the bottom of a huge air ocean called the atmosphere. All changes that occur in the atmosphere certainly have an impact on a person, on his health, lifestyle, 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 focus 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 build a fountain on the terrace of his palace and ordered water to be supplied from a nearby lake using a suction pump. The invited Florentine craftsmen said that this was impossible because the water had to be sucked up to a height of more than 32 feet (more than 10 meters). They could not explain why the water is not absorbed to such a height. The Duke asked the great scientist of Italy to look into it Galileo Galilei. Although the scientist was already old and sick and could not engage in experiments, he nevertheless suggested that the solution to the problem lay in the area of ​​​​determining the weight of air and its pressure on the water surface of the lake. Galileo's student Evangelista Torricelli took up the task of resolving this issue. To test his teacher's hypothesis, he conducted his famous experiment. A glass tube 1 m long, sealed at one end, was completely filled 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 poured 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. To calculate the pressure of mercury in a tube means to calculate the pressure of the atmosphere. If atmospheric pressure increases or decreases, the column of mercury in the tube increases or decreases accordingly. This is how the unit of measurement of atmospheric pressure appeared - mm. rt. Art. – millimeter of mercury. While observing the level of mercury in the tube, Torricelli noticed that the level was changing, which meant that it was not constant and depended 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, it means cloudiness and moisture saturation in the air is expected. A Torricelli tube with a ruler attached represents the first instrument for measuring atmospheric pressure - a mercury barometer. (Annex 1)

Other scientists also created barometers: Robert Hooke, Robert Boyle, Emil Marriott. 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, and in the SI system - Pascals.

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 barometer readings.

“Captain Gul, a good meteorologist, taught him to understand the barometer readings. 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 sure sign rain. However, if good weather stood for a very long time, the mercury column can drop for two or three days, and only after that any noticeable changes will occur in the atmosphere. In such cases, the more time passed between the beginning of the mercury fall and the beginning of the rains, the longer it will stand rainy weather.
2. On the contrary, if during a long period of rain the barometer begins to rise slowly but continuously, the onset of good weather can be confidently predicted. And good weather will remain the longer, the more time has passed between the beginning of the mercury rise and the first clear day.
3. In both cases, a change in weather that occurs immediately after the rise or fall of the mercury column persists for a very short time.
4. If the barometer rises slowly but continuously for two or three days or longer, this portends good weather, even if it has been raining non-stop all these days, and vice versa. But if the barometer rises slowly on rainy days, and immediately begins to fall when good weather comes, 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, a rapid drop in the mercury column indicates an upcoming change in wind direction, accompanied by thaw and rain. On the contrary, an increase in mercury during prolonged frosts foretells snowfall.
6. Frequent fluctuations in the level of the mercury column, sometimes rising, sometimes falling, should in no case be considered as a sign of the approach of a long period; period of dry or rainy weather. Only a gradual and slow fall or rise in the mercury heralds the onset of a long period of stable weather.
7. When, at the end of autumn, after a long period of wind and rain, the barometer begins to rise, this heralds a north wind at the onset of frost.

Here are the general conclusions that can be drawn from the readings of this valuable device. Dick Sand was an excellent judge of the barometer's predictions and was convinced many times how correct they were. Every day he consulted his barometer so as not to be taken by surprise by changes in the weather.”

I made observations of weather changes and atmospheric pressure. And I became 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

Instruments for measuring atmospheric pressure

For scientific and everyday purposes, you need to be able to measure atmospheric pressure. For this there are special devices – barometers. Normal atmospheric pressure is the pressure at sea level at a temperature of 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 mmHg. Art. Moreover, with increasing altitude, atmospheric pressure decreases, and with decreasing altitude, it increases.

The modern barometer is made liquidless. It's called an aneroid barometer. Metal barometers are less accurate, but not as bulky or fragile.

- a very sensitive device. For example, when climbing to the top floor of a nine-story building, due to differences in atmospheric pressure at different altitudes, we will find a decrease in atmospheric pressure by 2-3 mm Hg. Art.

A barometer can be used to determine the flight altitude of an aircraft. This 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 altitude above sea level by changes in atmospheric pressure.

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

(Storm Glass) (stormglass, Dutch. 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, stormglass is also called the "Fitzroy Barometer". From 1831–36, Fitzroy led the oceanographic expedition on HMS Beagle, which included Charles Darwin.

The barometer works as follows. The flask is hermetically sealed, but, nevertheless, the birth and disappearance of crystals constantly occurs in it. Depending on upcoming weather changes, crystals form in the liquid various shapes. Stormglass is so sensitive that it can predict sudden weather changes 10 minutes in advance. The principle of operation has never received a complete scientific explanation. The barometer works better when located near a window, especially in reinforced concrete houses; probably in this case the barometer is not so 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: A glass jar with a volume of 0.5 liters.

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

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

When atmospheric pressure changes in liquid barometers, the height of the liquid column (water or mercury) changes: when the pressure decreases, it decreases, when the pressure increases, 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:

Pressure in a liquid or gas is transmitted equally in all directions and does not depend on the orientation of the area 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 must be in a state of indifferent equilibrium in the liquid. 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 per 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. Pressure force on the bottom of a cylindrical vessel of height h and base area S equal to the weight of a column of liquid mg, Where m = ρ ghS is the mass of the liquid in the vessel, ρ is the density of the liquid. Therefore p = ρ ghS / S

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

Many devices we encounter in life use the laws of liquid and gas pressure: communicating vessels, water supply, hydraulic press, sluices, fountains, artesian well, etc.

Conclusion

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

Even in ancient times, doctors wrote about the influence of weather on the human body. In Tibetan medicine there is a mention: “joint pain increases during rainy times and during big winds" The famous alchemist and 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, a person feels uncomfortable and this can affect his health. Adverse phenomena are observed during the period of changes in atmospheric pressure - increase (compression) and especially its decrease (decompression) to normal. The slower the change in pressure occurs, the better and without adverse consequences the human body adapts to it.

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Introduction

Main part

Theoretical part

Practical part

Research on addiction blood pressure from the atmospheric method of social survey (Internet survey)

Conclusion

Bibliography

Introduction:

The effects of atmospheric pressure and atmospheric phenomena(thunderstorm, hot and dry winds, fog, snowfall, etc.), according to various scientists, affect the well-being of approximately 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 “weather 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 influencing well-being in general. And we want to focus on the specific influence of atmospheric pressure (its changes) on the value of blood pressure. At the same time, we tried to specify the problem and dwell on the effect of changes in atmospheric pressure on the blood pressure of adolescents.

In adolescence, health problems often arise that are temporary, that is, they go away with age. This is due to the fact that during the period of rapid growth and development of the body, many human organs and functions develop at different rates. Among other things, it is also influenced by the fact that it is during adolescence that serious hormonal changes occur 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 teenagers know what exactly these changes can be associated with, then it will be easier for them to perceive and survive 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 above, we believe that studying this problem is important, necessary and interesting.

Purpose of the study

Research objectives:

assess respondents' opinions on this issue

find out the opinion of medical workers who are directly involved in working with adolescents on this issue

experimentally identify the dependence of blood pressure on atmospheric pressure in adolescents

Research hypothesis:

Research methods:

study of literary sources and Internet resources on the research topic

method of direct measurement of atmospheric and blood pressure

For 10 days in a row, we measured blood pressure in a group of subjects aged 13 and 14 years old (we used the help of classmates). At the same time, we measured atmospheric pressure with a barometer.

method of analyzing and comparing the obtained measurement results

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

social survey method (Internet survey)

Taking advantage of the capabilities of the Internet, we invited teenagers completely unknown to us to answer several questions on the topic of our research. We believe that the Internet allows us to survey a large number of people in a short time and thereby make statistical data more 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 we ourselves began to understand more and more the relevance of this problem in the process of working on the research. Here are the main points of relevance of the problem of the dependence of blood pressure of adolescents (and its changes) on the value of atmospheric pressure:

it affects human health

the term "meteosensitivity" implies dependence on a number of atmospheric changes, without specifically highlighting atmospheric pressure

we ourselves are teenagers 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

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.

Pressure in the SI system is measured in pascals: [p]=Pa

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

The following pressure units are also used:

Bar , T technical atmosphere, physical atmosphere , meter of water column , inch of mercury , lbf per square inch .

The pressure of gases and liquids is measured using manometers, differential pressure gauges, vacuum gauges, atmospheric pressure - with barometers, blood pressure - with tonometers.

Atmosphere pressure:

The atmosphere is the air envelope of the Earth. Air is a mixture of gases, the main ones being nitrogen and oxygen. The Earth's atmosphere extends over several thousand kilometers and its density decreases with distance from the Earth's surface.

The mass of the modern atmosphere is approximately one millionth the mass of the Earth. With height, 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 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 has a very large ecological significance. It protects all living organisms of the Earth from the harmful effects of cosmic radiation and meteorite impacts, regulates seasonal temperature fluctuations, balances and equalizes the daily cycle. If the atmosphere did not exist, then the vibration daily temperature on Earth would reach ±200 °C.

We are accustomed to perceive the presence of atmosphere as a fact, but atmospheric air it just seems weightless to us. 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 - formula for calculating the weight of a body of known mass

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

Weight of 1 m3 of air:

Р=1.29kg/m3.1m3.9.8N/kg ≈ 13 N

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

Atmospheric pressure is 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 towards the Earth.

Normal atmospheric pressure is a pressure of 760 mmHg at sea level at a temperature of 15 0 C (or 101,325 Pa.) In superficial calculations, normal atmospheric pressure is considered to be 100 kPa.

When reporting on the weather on the radio, the announcers usually end by saying: atmospheric pressure 760 mmHg (or 749, or 754...). But how many people understand what this means and where weather forecasters get this data from?

Atmospheric pressure is measured in order to more likely predict possible weather changes. There is a direct connection between pressure changes and weather changes. An increase or decrease in atmospheric pressure with some probability can serve as a sign of weather changes. A decrease in pressure is followed by cloudy, rainy weather, and an increase is followed by dry weather, with severe cooling in winter.

Arterial 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 common measurement is blood pressure; In addition to it, the following types of blood pressure are distinguished: intracardiac, capillary, venous.

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

The top number is systolic blood pressure, which shows the pressure in the arteries when the heart contracts and pushes blood into the arteries. The bottom number is diastolic pressure, which shows the pressure in the arteries at the moment the heart muscle relaxes. Diastolic pressure is the minimum pressure in the arteries. As blood moves through the vascular bed, the amplitude of blood pressure fluctuations decreases; venous and capillary pressure depend little on the phase of the cardiac cycle.

A typical healthy person's arterial blood pressure (systolic/diastolic) = 120/80 mmHg. 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 mmHg. Art.

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

Modern digital semi-automatic tonometers allow you to limit yourself to only a set of pressure (until a sound signal), further release of pressure, registration of systolic and diastolic pressure, the device carries out itself.

Influence various factors on blood pressure indicators

Blood pressure depends on many factors:

time of day,

psychological state person (under stress, blood pressure increases),

taking various stimulants (coffee, tea, amphetamines) or medications that increase blood pressure.

on 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 resistance to blood,

on the volume of circulating blood and its viscosity,

person's age

The influence of atmospheric pressure on the value of human blood pressure:

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

Meteosensitivity

Weather sensitivity is the body's reaction to the effects of meteorological (weather) factors. Meteosensitivity is quite widespread and occurs with any, but more often unusual for this person climatic conditions. About a third of the inhabitants of temperate latitudes “feel” the weather. The peculiarity of these reactions is that they occur in a significant number of people synchronously with changes in meteorological conditions or somewhat ahead of them.

Meteorological sensitivity has long caused surprise and even fear of people before an incomprehensible natural phenomenon. People who sense the weather were called “living barometers”, “petrels”, “weather prophets”. Already in ancient times, doctors guessed about the influence of weather on the body. For a healthy person, meteorological fluctuations are usually not dangerous. Nevertheless, people who do not feel the weather still exhibit reactions to it, although sometimes they are not consciously aware of it. They must be taken into account, for example, among transport drivers. When weather conditions change sharply, it becomes more difficult for them to concentrate. This may increase the number of accidents. As a result of illnesses (flu, sore throat, pneumonia, joint diseases, etc.) or fatigue, the body's resistance and reserves are reduced. That is why meteosensitivity is observed in 35-70% of patients with various diseases. Thus, 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 - become distorted and become chaotic. The physiological (asymptomatic) weather reaction can be compared to a calm lake along which waves flow from a light breeze. A pathological (painful) weather reaction represents a kind of vegetative “storm” in the body. Dysregulation of the autonomic system contributes to its development. nervous system. Number of autonomic disorders in Lately increases, which is associated with the effect of unfavorable factors of modern civilization: stress, haste, physical inactivity, overeating and undereating, etc. In addition, different people The functional state of the nervous system is far from the same. This determines the fact that often diametrically opposed weather reactions are observed for the same diseases: favorable and unfavorable. More often, meteosensitivity is observed in persons with a weak (melancholic) and strong unbalanced (choleric) type of nervous system. In people of a strong, balanced type (sanguine people), meteosensitivity manifests itself only when the body is weakened. The body is affected by both the weather as a whole and its individual components.

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

reduce blood oxygen saturation (the effect of barometric “holes”)

mechanically irritate the nerve endings (receptors) of the pleura (the mucous membrane lining the pleural cavity), the peritoneum (lining abdominal cavity), synovial membrane of 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 pressure. Thus, with a decrease in blood pressure, people suffering from rheumatism experience pain in the affected joints; in patients with hypertension, their health worsens and attacks of angina are observed. In people with increased nervous excitability, sudden changes in pressure cause feelings of fear, worsening 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 in a certain area for quite a long time 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 reduction in heart rate and a decrease in minimum blood pressure. Breathing becomes rarer but deeper. Hearing and smell are slightly reduced, the voice becomes muffled, a feeling of slightly numb skin appears, dry mucous membranes, etc. However, all these phenomena are relatively easily tolerated.

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

With reduced atmospheric pressure, there is increased and deepening of breathing, increased 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. The adverse effect of low atmospheric pressure on the body is based on oxygen starvation. It is due to the fact that as atmospheric pressure decreases, 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 total atmospheric pressure. This contribution of individual oxygen is the partial pressure of this gas. Consequently, as atmospheric pressure decreases, the partial pressure of oxygen also decreases, which leads to oxygen starvation and, with the normal functioning of the respiratory and circulatory organs, less oxygen enters the body.

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

II.II Practical part

II.II.I Study of the problem of dependence of blood pressure on atmospheric pressure using the method social survey (online survey)

using a social survey (Internet survey) to find out the opinion of the target audience about the possibility of a person’s blood (arterial) pressure depending on atmospheric pressure.

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

Questions asked:

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

Methodology for analyzing the results:

Questionnaires from respondents who chose the following answer options 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 low or high blood pressure?
	Are you interested in the atmospheric pressure value indicated in the weather forecast? (or measure yourself)
	Do you think changes in your blood pressure are related to changes in barometric pressure?

As a result, we accepted for processing questionnaires from respondents who were ready to help us, who were teenagers (we slightly expanded the age range), who had problems with blood pressure and who had an understanding of atmospheric pressure. To simplify the data processing process, we stopped the online survey at the hundredth questionnaire that met 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: teenagers do not have special medical education, do not measure blood pressure every day, and may have other health problems that affect blood pressure values. Therefore, the results of a social survey express only the audience’s opinion on this issue, and not the direct relationship of the phenomena under consideration.

Study of the problem of dependence of blood pressure on atmospheric pressure using interviewing method

Task this stage research: find out the opinion of medical workers who are directly involved in working with adolescents on this issue.

Interview with school paramedic Kostyakova Svetlana Valerievna:

Question: please tell me how often do teenagers come to you with the problem of high or low blood pressure?

Answer: Very often, during a medical examination, we identify a number of problems directly related to deviations from the norm in blood pressure.

Question: What do you think this might be connected with?

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 adapt correctly and quickly to such changes. According to statistics, teenagers in regions with a more stable climate suffer much less from such deviations

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

Question: do you believe that many healthy people Are they weather dependent?

Answer: You know, now some St. Petersburg medical centers specialize in correcting weather dependence. Entire techniques have been developed, including herbal medicine, therapeutic exercises, breathing exercises and much more. But these clinics mainly specialize in treating middle-aged and elderly people, or people with chronic pathologies in this area. And among teenagers, weather dependence can be a temporary, age-related problem. But if a teenager is sure that weather changes affect his condition, no one is stopping him from taking an interest in the weather forecast in advance and, based on this, making his plans for the coming days. Nature still has many secrets and questions to which there are no concrete answers yet.

Study of the problem of the dependence of blood pressure on atmospheric pressure using an experimental method.

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

Progress of the experiment: Blood pressure was measured for 10 days in eight subjects aged 13 and 14 years. At the same time, we measured atmospheric pressure with a barometer, checking the readings with the meteorological forecast for these days. The difference between the experimental values ​​of atmospheric pressure and the meteorological forecast data turned out to be insignificant. Therefore, for comparison and analysis, we used data obtained independently during the experiment.

Data processing technique: we entered the direct measurement data into a table (see below). During 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 a table (see below). The following graphs turned out to be more clear, which allowed us to draw a conclusion that practically confirmed our hypothesis.

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

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

Graph No. 1: atmospheric pressure value

Graph No. 2: blood pressure value of two subjects

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

Based on the fact that when comparing direct measurement data the conclusion is not entirely obvious, we hypothesized that the relationship may exist not so much between absolute pressure values, but between changes these values.

Table No. 2

Modulus of the difference between the current pressure value and the next one

in mmHg (∆ p)

	atmospheric

Graph No. 3: change in atmospheric pressure

Chart No. 4

Comparison of changes in atmospheric and blood pressure

Diagram No. 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 claim 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 claim that blood pressure depends from the atmospheric, more preciselychanges atmospheric pressure lead tochange blood pressure in adolescents.

Conclusion

The study of the connection 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 Terrains” outlined the essence of the influence of weather on humans. Nowadays, this problem is studied mainly by medical centers specializing in the treatment of hypotension and hypertension. For our study, we chose one of the aspects of meteosensitivity - the influence of atmospheric pressure on the well-being of adolescents.

The purpose of our study was: to study the dependence of changes in blood pressure in adolescents on changes in atmospheric pressure.

We assumed that such a dependence exists, therefore we put forward a hypothesis about the existence 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 online survey among large group teenagers, the result turned out to be very clear - 65% of respondents are inclined to consider the hypothesis we put forward to be correct. Then we were interested in the question of what medical workers directly related to working with adolescents think about the influence of atmospheric pressure on the health of schoolchildren. From interviews with a teenage doctor and a school paramedic, we received a lot of useful and revealing information, which also practically confirms our hypothesis. Next, it seems appropriate to us to quote the famous philosopher, inventor and painter Leonardo da Vinci. He claimed that:

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

Those who, when studying science, turn not to nature, but to authors, cannot be considered 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 blood and atmospheric pressure of adolescents for 10 days and further analysis of the data obtained.

We believe that we have completed the assigned tasks and present to your attention specific conclusions for each of the assigned tasks, as well as a general conclusion corresponding to the stated goal of the work:

General conclusion:

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

We have only covered a small aspect common problem influence of atmospheric phenomena on human health. In progress research work we got a lot 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 online resources:

Kuznetsov B.G. Paths of physical thought. - M.: Nauka, 1968, 350 pp.

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

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

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

Simanov Yu. G. Live barometers. - M.: Znamya, 1986, 128 pp.

Schoolchild's encyclopedia: 4000 fascinating facts. - M.: Makhaon, 2003, 350 pp.

http//ru.wikipedia.org

http/www.d-med.org

STATE BUDGETARY EDUCATIONAL INSTITUTION OF SECONDARY

PROFESSIONAL EDUCATION OF THE ROSTOV REGION

"KAMENSKY TECHNIQUE OF CONSTRUCTION AND AUTO SERVICE"

Search and research work

on this topic:

“The pressure is obvious and necessary”

Completed:

students of group No. 14

Bulgakov Alexander

Khomenko Alexander

Leaders:

Physics teacher Semikolenova

Natalya Anatolyevna

Foreman Myachin Viktor Mikhailovich

Kamensk-Shakhtinsky

2014

Content

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

1. Description and progress carrying out the work….………………………..………………..

1.1. History of the study of “Pressure”………………………………………….….

1.2. Instruments for measuring pressure……………………………………..

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

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

…………………………………………………..

2.1 Experiments to demonstrate pressure …………………………………………

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

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

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

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

Applications………………………………………………………………………………………….

Introduction

Pilots say that air is what gives support to our wings. Without air, planes could not fly. Doctors say that air is what we breathe. You can't live without air! And engineers say: “Air is an excellent worker. True, he is free, flying, you can’t 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 on buses, trolleybuses and trains, it softens all shocks and impacts 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, and on the other hand, by improving methods technical operation cars.

Pressure is one of the most important parameters various processes. That is why our search engine research project called: “Pressure is obvious and necessary.”

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

The contradictions of 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 study is a set of experiments that help demonstrate atmospheric pressure and its practical use.

The purpose of our research is to demonstrate atmospheric pressure and its application, both at the domestic and professional level.

To implement the search and research work, we had to solve a number of problems in several areas:

study historical facts on the accumulation and systematization of knowledge about “Pressure”;

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

study instruments for measuring pressure:

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

    study the device and principle of operationinstruments for measuring pressure;

identify factors influencing changes in pressure incar tires Oh;

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

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

draw a graph of pressure dependence incar tires on air temperature;

When carrying out 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 search and research work, we identified: demonstration of the manifestation of pressure and its practical and professional use and the assumption that systematic monitoring of wheel pressure will significantly increase the service life of car tires.

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

Preparatory;

Basic:

search and research;

evaluative-reflective;

Final

Description and progress of the study

In Physics classes, studying the section “Fundamentals of molecular kinetic theory,” we became acquainted with the manifestation of gas pressure. We found this topic interesting for in-depth study. We determined the topic of the search and research work: « The pressure is obvious and necessary,” they identified a number of tasks and began to solve them.

To begin with, we decided to study the historical aspect of this issue. We wanted to know which 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 era early Middle Ages the idea of ​​the atmosphere was expressed by the Egyptian scientist Al Haithamah (Alghazena). 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 statement of the ancient Greek scientist Aristotle that water rises behind the pump piston was considered indisputable because “nature is afraid of emptiness.”.

This statement led to confusion in 1638, when the Duke of Tuscany’s idea 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 it is likely that nature 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 atmospheric pressure.

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

Otto von Guericke, the burgomaster of the city of Magdeburg, studied atmospheric pressure extensively and fruitfully. In May 1654, He conducted an experiment that provided clear evidence of the existence of atmospheric pressure.

For the experiment, two metal hemispheres were prepared (one with a tube for pumping out air). They were placed together, and a leather ring soaked in melted wax was placed between them. Using a pump, air was pumped out from the cavity formed between the hemispheres. Each hemisphere had a strong iron ring.
Two eight horses harnessed to these rings pulled in different directions, trying to separate the hemispheres, but they failed. When air was allowed inside the hemispheres, they disintegrated without external force.

1.2 Pressure measuring instruments

The ability to measure atmospheric pressure is of great practical importance. This knowledge is necessary in weather forecasting, medicine, 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) pressure gauges - for measuring absolute and gauge pressure;

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

c) pressure and vacuum gauges - for measuring excess pressure and vacuum;

d) pressure meters - for measuring small excess pressures (upper measurement limit not more than 0.04 MPa);

e) draft gauges - for measuring small vacuums (upper limit of measurement up to 0.004 MPa);

f) draft pressure meters - for measuring vacuums and small excess pressures;

g) differential pressure gauges - for measuring pressure differences;

h) barometers - for measuring barometric pressure of atmospheric air

Using different types 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 devoted the next point of our work to solving this problem.

Pressure gauges are used in all cases where it is necessary to know, control and regulate pressure.

Pressure gauges are divided into 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 tire pressure gauges for measuring air pressure in tires.The most simple option The tire pressure monitoring sensor is a mechanical sensor.

They there may be arrows -They are quite accurate, but they are “afraid” of falls and overload with high pressure, due to which the pressure gauge spring inside the pressure gauge deteriorates.

Mechanical pressure gauges in the form of a “handle”, with a cylindrical spring, are much more reliable, but, as a rule, have less measurement accuracy.

Pressure sensor in the form of caps - fits onto the tire valve. Its operating principle is the mechanical movement of the piston depending on the pressure.

With a nominal sensor pressure of 2 bar, this device shows green color. If the pressure has dropped to 1.7 bar, a yellow indicator appears. When the tire pressure level 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 the 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 main block, which displays information on the display in the car. To ensure that the service life of the vehicle's electrical sensor is not too short, signals are sent to the unit every 15 minutes when the vehicle is parked, and every 5 minutes when driving. But if the pressure changes (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 beaded and the sensor is mounted directly on the rim of the disk near the valve, then the tire is put in place and balanced taking into account the weight of the sensor, because its mass is about 30 grams. The only disadvantage of such a device is the complexity of installation, while the advantage is the high tightness of the system.

Electrical pressure sensors - microchips. Microchips are very complex, since a chip is installed inside the tire, where all the information about the tire is stored, that is, its type, size, permissible load, maximum speed, recommended pressure and date of manufacture. All this is carried out at the manufacturer's factory. 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

A tire is one of the main elements of a car and significantly affects its performance. The traction and braking characteristics of the vehicle, its stability, traffic safety, smoothness, and efficiency depend on the tires.

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

Some car tires indicate the recommended pressure so that the driver can see at what pressure they remain operational, that is, they do not collapse.

It is important that the air pressure, within certain limits, can easily vary depending on operating conditions, as a result of which it is possible to influence the resistance of tires to slip during vehicle operation in a desired manner.

Weather conditions have a significant impact on tire air pressure. The air pressure in the tires changes with sudden changes in weather, from the temperature of the asphalt heated in the sun during the day, from the increase in the temperature of the wheels due to friction forces.

In a tire inflated according to the instructions (Appendix 3), the air pressure helps uniform distribution loads in the contact patch, which ensures the stability of the tire structure. This is known to affect wear patterns, 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..

An underinflated tire's shoulder area wears out faster than the middle of the tread (Fig. 1).

Reduced pressure makes the wheel softer and the ride more pleasant, since all road irregularities are absorbed. 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, and its frame is destroyed. In addition, hydroplaning and grip on wet roads worsen.

Fig.1 Tire wear at different pressures

In connection with the above, we can conclude that during the rolling process, forces of different magnitudes and directions act on the tire, which in turn largely depend on the external load and ambient temperature.

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

2.1 Experiments to demonstrate pressure

To implement this point of work, we selected a set of experiments, the material and technical base for conducting them and demonstrating the existence of atmospheric pressure and its practical application in various fields of human activity.

Experience No. 1

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

Carrying out: Fill the glass to the brim with water and cover it with a sheet of paper. Supporting the sheet with your hand, turn the glass upside down. When you take your 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 No. 2



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

Carrying out: We took a bottle without plasticine. They 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 completely.

Explanation: Water flows freely into the first bottle. Since it replaces the air in it, which comes out through the gaps 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 arises due to the force of gravity pulling the water down. However, the force of air pressure in the bottle exceeds the force of gravity acting on the water. Therefore, water cannot enter the bottle.

Experience No. 3



Equipment: ruler 50 cm long, newspaper.

Carrying out: Place 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. They made one karate blow on the ruler - the ruler cannot lift the newspaper or breaks.

Explanation: Atmospheric air exerts pressure on the newspaper from above. The air pressure on the newspaper from above is greater than from below, and the ruler breaks .

Experience No. 4



Equipment: baking dish, water, ruler, gas or electric stove (only for adult use), empty can, forceps.

Carrying out: We poured about 2.5 cm of water into the mold. We placed it next to the stove. We poured some water into an empty soda can so that the water just covered the bottom. After this, the assistant heated the jar on the stove. Let the water boil vigorously, for about a minute, so that steam comes out of the jar. We took the jar with tongs and quickly turned it into a mold with water. The tin flattened as soon as the water touched it .

Explanation: The can collapses due to changes in air pressure. A low pressure is created inside it, and then it is crushed by higher pressure. 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 the assistant lowers the upside down can, the air cannot return to it again. The cold water in the mold cools the steam remaining in the jar. It condenses - turns from gas back into 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. There remains a large empty space in the jar, 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 collapses.

These and many other experiments really are proof that atmospheric pressure exists and affects us and the objects around us

2.2 Experiments to demonstrate the practical use of pressure

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

Experience No. 5



Equipment: straw, glass of drinking water.

Carrying out: bring a glass of water to your mouth and “draw in” the liquid

Explanation: When drinking, we expand our chest and thereby thin out the air in our 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 No. 6



Equipment: a jar filled with water, a trough.

Carrying out: fill the jar with water. Place it upside down in the trough so that the neck is slightly below the water level in it. We received an automatic bird drinker.

Explanation: When the water level drops, some of the water from the bottle will spill out.

Experience No. 7



Equipment: shows 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 top 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 top hole is closed, the atmosphere exerts pressure only from below, otherwise it squeezes the liquid out of the liver.

Experience No. 8



Equipment: 1 - plastic bag, 2 - glass tube, 3 - rubber balloon, 4 - two thick wire rings, 5 - thread.

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

We have given some examples of the use of atmospheric pressure in everyday life (see Appendix 4), the manifestation of this in our professional activities will be discussed in the next paragraph of our work

2.3 Tire pressure and temperature

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

1 day

Temperature, 0 C

Pressure, bar

2,15

2,25

2,30

Day 2

Temperature, 0 C

Pressure, bar

2,16

2,26

2,31

Day 3

Temperature, 0 C

Pressure, bar

2,25

2,32

Correctly set tire pressure increases tire life and also ensures safe driving. A driver who cares about his safety and the safety of his car should install tire pressure sensors. These electronic monitoring systems allow you to constantly monitor the pressure and temperature inside the tires, so you can track any wheel failure

Conclusion

In the course of our research, we found out how important knowledge about the existence of atmospheric pressure is, that nothing other than atmospheric pressure can explain the occurrence of many physical phenomena. We were surprised that it is atmospheric pressure that determines many processes in human life and activity. In addition, factors influencing the operating efficiency of car tires were identified. determined that tire pressure affects the traction, braking, characteristics of the vehicle, its stability, traffic safety, smoothness, efficiency, and the service life of the tires themselves.

We studied the operating principle, advantages and disadvantages of each type of tire pressure sensor.

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

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

systematically diagnose tire pressure, taking into account weather conditions;

Carry out additional inspection of the car before long trips.

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

This work deepened our knowledge of “Pressure” and expanded our understanding of the areas of its manifestation and application. In addition, we consider it advisable to continue studying the effect of pressure on other vehicle components.

Literature

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

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

Fireplace A.L.. Physics. Developmental training. 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.: AST Publishing House LLC, 2001.

Fundamental research //scientific journal No. 8, 2011

Remote access electronic resources

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 dyn/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 mmHg

133,322

1.3332·10 −3

1.3595 10 −3

1.3158 10 −3

1 mmHg

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 pointer pressure gauge

(gauge tube)

Mechanical pressure gauge (coil spring)



Mechanical pressure gauge in the form of caps,

which fit onto the tire nipple



Electrical sensors and

receiving information block



Electrical sensor,

mounted on car rims



Electrical pressure sensors - microchips

1 – valve; 2 – wheel rim; 3 – chip; 4 – tire

Appendix 3

Specifications some cars

Car make

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

Car make

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

260-508Р

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, jars, syringes, liver

In human life

children's toys with suction cups, soap dishes with suction cups, plunger, canning, fountains, liquid intake with a hose, hip bones.

In nature

snowflakes different shapes

In the life of animals

octopus, leeches, sucker flies, complex hooves of pigs, ruminants, elephant trunk

Agriculture

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

Meteorology

weather prediction, folk signs, natural “barometers”