Description: War Thunder is a next generation military MMO game dedicated to...
- Earth's atmosphere. Atmosphere pressure.
- History of the discovery of atmospheric pressure
- Evidence for the existence of atmospheric pressure
- The effect of atmospheric pressure on humans, use in the human body
- Atmospheric pressure is the pressure exerted by the atmosphere on all objects in it and the Earth's surface.
- For the first time, air was weighed by Galileo, before him it was believed that air was weightless.
- Calculate the force with which the air presses on the area of \u200b\u200bthe notebook opened in front of you. Atmospheric pressure is normal 101300 Pa.
- The surface area of the human body is about 15,000 cm2. Calculate the force with which the air presses on a person. Atmospheric pressure is taken equal to 101300 Pa.
- 10 cm of water was poured into a glass with a bottom area of 0.002 m2. Calculate the weight of the water and the bottom pressure. Compare this pressure with normal atmospheric pressure.
- I succeeded the most...
- I can commend myself for...
- I can praise my classmates for...
- I was surprised...
- It was a revelation for me that...
- In my opinion it didn't work...because...
- For the future, I will...
- If the Earth's atmosphere did not rotate along with the Earth around its axis, then the strongest hurricanes would arise on the Earth's surface.
- According to Pascal's calculations, the Earth's atmosphere weighs as much as a copper ball with a diameter of 10 km would weigh - five quadrillion (5000000000000000) tons!
- - on Earth, the temperature would be approximately -170 ° C, all water spaces would freeze, and the land would be covered with an ice crust.
- - there would be complete silence, since sound does not propagate in the void; the sky would become black, since the color of the firmament depends on the air; there would be no twilight, dawns, white nights.
- - the twinkling of stars would stop, and the stars themselves would be visible not only at night, but also during the day (we do not see them during the day due to scattering by air particles sunlight).
- - Animals and plants would die.
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We are sunk to the bottom of the boundless
seas air element, which
has weight, and it is the largest in
the surface of the earth.
E. Torricelli (1644)
slide 3
Better to see once than hear a hundred times!
Of course we can't see Atmosphere pressure, but we can empirically evaluate its effect on various bodies.
Experience "Don't go into the bottle"
Experience "Strongman Invisible"
Experience "Dry out of water"
The newspaper experience
Do the experiments yourself
slide 4
slide 5
Experience "Strongman Invisible"
Pour a little water (about a spoonful) into the tetrapack, without closing, put it to heat. The water in the jar will boil and you will see how the steam comes out of the neck. Gently screw on the lid (the paper tetrapack does not heat up and can be taken without fear by hand). Put it in a deep plate and pour cold water over it. And then a miracle, an invisible force will crush the package.
slide 6
Experience No. 4 "With a newspaper"
Lay a long wooden ruler on the table so that its end extends over the edge of the table. Cover the table with a newspaper on top, or smooth the newspaper with your hands with a Whatman paper so that it lies snugly on the table and ruler. Hit the free end of the ruler sharply - the newspaper will not rise, but will tear, in the case of whatman paper the ruler will bend and fly out or break, then fold the newspaper several times and put it on the ruler again, in this case it will fly away.
Slide 7
The word atmosphere was first introduced into Russian science by our compatriot, the great Russian scientist
M. V. Lomonosov.
Slide 8
We know that gas molecules move randomly at high speeds. But at the same time, the bulk earth's atmosphere located at an altitude of no more than 10 km from the Earth, because due to gravity, air molecules cannot fly far from the surface of the earth.
Slide 9
Air, like any body on Earth, is affected by gravity, and, therefore, air has weight.
Experiments demonstrating the presence of weight in air.
Balloon experience.
Experience the weight of the air
Slide 10
Experience "Balloon Air Weight"
Take two balloons and blow them up.
Glue a piece of tape on one of the balls.
Tie the balls to the arms of the balanced weights.
Pierce the balloon through the tape, holding it with your hand, a piece of tape will not allow the balloon to shatter into pieces.
When the movement of the scales stops, you will see that the balloon with air weighs more.
slide 11
Experience "Weight of Air"
We will show by experience how to determine the mass of air. To do this, you can take a strong glass ball with a cork and a rubber tube with a clamp. We pump air out of it with a pump, clamp the tube with a clamp and balance it on the scales. Then, opening the clamp on the rubber tube, let air into the ball. In this case, the balance of the scales will be disturbed. To restore it, you will have to put weights on another scale pan, the mass of which will be equal to the mass of air in the volume of the ball. It has been empirically established that at t=0 C at sea level, the air density is p =1.29. The weight of this air is easy to calculate: P= mg, P= pVg.
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Ostap Bender declares his love:
You know Zosya… an atmospheric column weighing 214 kilos presses on everyone. Didn't you notice it?
It seems to me that the atmospheric column presses on me much more than on other citizens. It's out of love for you.
It's not a lie, it's a law of physics.
Did Ostap correctly estimate the weight of the pole?
Why don't people notice this weight?
slide 13
Why can't we feel atmospheric pressure?
Meanwhile, its pressure is very high and amounts to about 1 kg per square centimeter of the body surface. The latter in a person of average height and weight is 1.7 m2. As a result, the atmosphere presses on us with a force of 17 tons! We do not feel this huge squeezing effect because it is balanced by the pressure of body fluids and gases dissolved in them.
Slide 14
Find out with what force the atmosphere presses on you!
In order to find out with what force the atmosphere presses on you. You need to find out the volume of the body, this is easiest to do in the bathroom. Fill the bathtub with water and use a felt-tip pen to note its level. Immerse yourself in the bath, the water level will rise, displacing exactly the volume of your body. Ask an assistant to replace the level of the rising water.
Calculating the volume of water comes down to calculating the area of the parallelepiped (curves can be neglected, this will not significantly affect the calculations).
To calculate the force with which the atmosphere presses on you, you need to multiply the resulting volume by the atmospheric pressure expressed in Pascals.
slide 15
Fluctuations in atmospheric pressure cause a number of shifts in the body, which is especially felt by patients with hypertension and joint diseases. After all, when the atmospheric pressure changes by 25 mm Hg. Art. the pressure of the atmosphere on the body changes by more than half a ton! The body must balance this pressure shift.
slide 16
Breathing mechanism
The mechanism of human breathing is as follows: with muscle effort, we increase the volume chest, at and atmospheric pressure pushes a portion of air there. When exhaling, the reverse process occurs. Our breathing apparatus acts now as a dilution pump, now as a pressure pump.
Slide 17
Model of external respiration
Slide 18
The greater the vital capacity of the lungs, the more well-being, diseases leave us, as the cells increase their potential and where more successfully breathe more freely, it improves resist the disease
Slide 19
respiratory gymnastics complex
Slide 20
Inhale deeply, hold your breath for 8 seconds and exhale slowly. Repeat this exercise 4 times.
Breathe in small amounts of air. Hold the breath for 8 seconds and exhale slowly. Repeat this exercise 4 times.
Breathe in small amounts of air. Hold the air for 8 seconds and exhale the air with small exhalations. Repeat this exercise 3 times.
Close the left nostril. Inhale slowly through the right nostril. Inhale air through your mouth. Repeat 2 times.
Block the right nostril. Inhale air through the left nostril. Exhale air through your mouth. Repeat 2 times.
Inhale air through the nose and exhale through the mouth. Repeat 3 times.
Close the right nostril, inhale the air. Then exhale the left nostril. Repeat 3 times.
Breathe slowly for 1 minute.
slide 21
decompression sickness
If a person very quickly rises by plane into the rarefied layers of the atmosphere, then above 19 km above sea level, complete sealing is needed. At this altitude, the pressure decreases so much that water (and therefore blood) boils no longer at 100 ° C, but at body temperature. There may be phenomena of decompression sickness, similar in origin to decompression sickness.
slide 22
Pepsi Decompression Experience
Pour Pepsi (any carbonated drink) into a glass and let the gas escape so that it does not bubble.
Place a cup under the bell of the vacuum pump and pump out the air.
Turn off the pump and let air in, you will see how the volume of liquid decreases.
slide 23
Another way to experience decompression
Pour Pepsi (any carbonated drink) into a flask with an airtight lid and a pump outlet and let the gas escape so that it does not bubble.
Fix the flask in a tripod and connect it to a vacuum pump, pump out the air.
As the pressure decreases, the liquid will begin to bubble.
Turn off the pump and let air in, you will see how the volume of liquid decreases
slide 24
the mountains
At an altitude of 3000 m and above (high mountains), due to a lack of oxygen, noticeable violations of a number of physiological functions of the body are usually noted. Starting from a height of 4000-5000 m, due to increasing oxygen deficiency, the so-called high-altitude or mountain sickness may occur.
Slide 25
divers
Divers and those who work in caissons - special chambers used in the construction of bridges and other hydraulic structures, are forced, on the contrary, to work at high blood pressure air. At a depth of 50 m under water, a diver experiences pressure almost 5 times higher than atmospheric pressure, and in fact he sometimes has to go down 100 m or more under water. Air pressure has a very peculiar effect. A person works in these conditions for hours without experiencing any trouble from increased pressure. However, with a quick rise up, sharp pains in the joints, skin itching, and vomiting appear; in severe cases noted deaths. Why is this happening?
slide 26
decompression sickness
in the fact that in the blood, as in any other liquid, with an increased pressure of the gases (air) in contact with it, these gases dissolve more significantly. Nitrogen, which makes up 4/s of air, is completely indifferent to the body (when it is in the form of free gas), dissolves in large quantities in the diver's blood. If the air pressure decreases rapidly, the gas begins to come out of solution, the blood "boils", releasing nitrogen bubbles. These bubbles are formed in the vessels and can clog the vital important artery- in the heart, brain, etc. Therefore, divers and working caissons are very slowly raised to the surface so that the gas is released only from the pulmonary capillaries
Slide 27
Leonov Alexey Arkhipovichspacewalk
He made his first flight into space on March 18-19, 1965, together with Pavel Belyaev, as a co-pilot on the Voskhod-2 spacecraft. Leonov was in open space 12 minutes 9 seconds
During the exit, the space suit swelled and prevented the astronaut from returning to spaceship. Leonov managed to enter the airlock only by venting excessive pressure from the suit.
Slide 28
Sources:
A.L. Fireplace "Physics and developmental education"
Ya. I. Perelman "Entertaining physics" book 1 page 94
A. A. Gurshtein "Eternal secrets of the sky"
J Walker "Physical fireworks".
Pictures:
hand image - http://subscribe.ru/group/lyubiteli-prirodyi/
Cloud image -blogs.privet.ru
Portrait of Torricelli - markapochtoy.in.ua
Portrait of M.V. Lomonosov contraindications.ru
Image molecule nerox.ucoz.ua
Image of a skydiver - http://x3mblog.ru/2009/08/17/b…
Image of Ostap Bender - http://kontrakty.ua/article/21
Image of Archimedes in a bathtub filled with water - super-day.ru
Image of a person who has a headache - http://inforotor.ru/catalogue/…
The mechanism of respiratory movements ... http://schemo.rf/shemy/b
Image of a cat - zhenskoe-mnenie.ru
Airplane image - ticetov.blogspot.com
Image of the Caucasus.Teberda lake. allday2.com
Image of a diver -saratovnews.ru
Forceful.r diver image
Portrait of cosmonaut Leonov - http://depdela.ru/leonov-aleksej-arkipovic
View all slides
slide 2
Presentation on the topic: ATMOSPHERIC PRESSURE
slide 3
Atmospheric pressure is the pressure force of the air column per unit surface area (the number of kg per 1 sq. cm). It is known that normal pressure acts on a square centimeter of our body as a weight of 1.033 kg. However, people's pressure atmospheric air does not bother, since in tissue fluids the dissolved gases of air balance everything.
slide 4
ATMOSPHERIC PRESSURE (Greek atmos - steam) - the gravity of the air column from its upper limit to the earth's surface or ground objects at a given altitude level. The weight of 1 liter of air at the level of the World Ocean is about 1.3 g, and its pressure reaches 1033 g/cm2. At sea level at a latitude of 45 ° at a temperature of 0 ° C Atmospheric pressure is equal to the weight of a mercury column of 760 mm or 1013 mblr, which is taken as normal pressure the globe. For every 10 m increase in altitude, atmospheric pressure decreases by 1 mm or 1.3 mlbar, as measured by a barometer. The pressure depends on temperature changes, and therefore, on the time of day, on the change of certain air masses (cyclones decrease, and anticyclones increase).
slide 5
Changes in atmospheric pressure within the atmosphere:
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Atmosphere - the air shell of the Earth / several thousand kilometers high /.
Slide 7
Having lost the atmosphere, the Earth would become as dead as its companion the Moon, where either sizzling heat or chilling cold reign alternately - + 130 C during the day and - 150 C at night.
Slide 8
According to Pascal's calculations, the Earth's atmosphere weighs as much as a copper ball with a diameter of 10 km would weigh - five quadrillion (5000000000000000) tons!
Slide 9
Story
The presence of atmospheric pressure confused people in 1638, 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 meters. The search for the reasons for this and experiments with a heavier substance - mercury, undertaken by Evangelista Torricelli, led to the fact that in 1643 he proved that air has weight. Together with V. Viviani, Torricelli conducted the first experiment on measuring atmospheric pressure, inventing the Torricelli tube (the first mercury barometer) - a glass tube in which there is no air. In such a tube, mercury rises to a height of about 760 mm.
Slide 10
Variability and impact on weather
On the earth's surface, atmospheric pressure varies from place to place and over time. Especially important are the weather-determining non-periodic changes in atmospheric pressure associated with the emergence, development and destruction of slowly moving regions. high pressure(anticyclones) and relatively fast moving huge eddies (cyclones), in which low pressure prevails. There were fluctuations in atmospheric pressure at sea level in the range of 641 - 816 mm Hg. Art. (inside the tornado, the pressure drops and can reach a value of 560 mm Hg). Atmospheric pressure decreases as altitude increases, since it is created only by the overlying layer of the atmosphere. The dependence of pressure on height is described by the so-called. barometric formula. On maps, pressure is shown using isobars - isolines connecting points with the same surface atmospheric pressure, necessarily reduced to sea level. Atmospheric pressure is a very variable weather element. From its definition it follows that it depends on the height of the corresponding column of air, its density, on the acceleration of gravity, which varies with the latitude of the place and the height above sea level.
slide 11
Standard pressure
In chemistry, since 1982, the standard atmospheric pressure, according to the IUPAC recommendation, is a pressure equal to 100 kPa. Atmospheric pressure is one of the most significant characteristics of the state of the atmosphere. In a resting atmosphere, the pressure at any point is equal to the weight of the overlying column of air with a unit cross section. In the GHS system 760 mm Hg. Art. equivalent to 1.01325 bar (1013.25 mbar) or 101325 Pa in international system units (SI). The equation of statics expresses the law of pressure change with height: -∆p=gρ∆z, where: p - pressure, g - free fall acceleration, ρ - air density, ∆z - layer thickness. It follows from the basic equation of statics that as the height increases (∆z>0), the change in pressure is negative, that is, the pressure decreases. Strictly speaking, the basic equation of statics is valid only for a very thin (infinitely thin) air layer ∆z. However, in practice it is applicable when the change in altitude is sufficiently small relative to the approximate thickness of the atmosphere.
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slide 13
baric stage
The height to which it is necessary to rise or fall in order for the pressure to change by 1 hPa (hectopascal) is called the baric (barometric) step. The baric stage is convenient to use when solving problems that do not require high accuracy, for example, to estimate pressure from a known height difference. From the basic law of statics, the pressure stage (h) is: h=-∆z/∆p=1/gρ [m/hPa]. At an air temperature of 0 °C and a pressure of 1000 hPa, the baric level is 8 m/hPa. Therefore, in order for the pressure to decrease by 1 hPa, you need to rise by 8 meters. With increasing temperature and increasing altitude above sea level, it increases (in particular, by 0.4% for each degree of heating), that is, it is directly proportional to temperature and inversely proportional to pressure. The reciprocal of the baric step is the vertical baric gradient, that is, the change in pressure when raising or lowering 100 meters. At a temperature of 0 °C and a pressure of 1000 hPa, it is equal to 12.5 hPa.
Slide 14
Adjustment to sea level
The reduction of pressure to sea level is carried out at all meteorological stations that send synoptic telegrams. To make the pressure comparable at stations located at different heights, the pressure reduced to a single reference mark - sea level is applied to synoptic maps. When reducing pressure to sea level, the abbreviated Laplace formula is used: z2-z1=18400(1+λt)lg(p1/p2). That is, knowing the pressure and temperature at the level z2, one can find the pressure (p1) at sea level (z1=0). Calculation of pressure at altitude h from sea level pressure Po and air temperature T:P = Poe-Mgh/RT where Po - pressure Pa at sea level [Pa]; M - molar mass of dry air 0.029 [kg / mol]; g - free fall acceleration 9.81 [m/s²]; R is the universal gas constant 8.31 [J/mol K]; T- absolute temperature air [K], T = t + 273, where t is the temperature in °C; h - height [m]. At low altitudes, every 12 m of ascent reduces atmospheric pressure by 1 mm Hg. Art. At high altitudes, this pattern is violated.
slide 15
Barometer
Atmospheric pressure is measured in millimeters of mercury (mmHg). To determine it, they use a special device - a barometer (from the Greek baros - gravity, weight and meter - I measure). There are mercury and non-liquid barometers.
slide 16
Mercury Aneroid
barometers
Slide 17
Barometer
Aneroid barometer: 1 - metal box; 2 - spring; 3 - transmission mechanism; 4 - arrow-pointer; 5 - scale
Slide 18
The Torricelli experience
The value of 760 mm was first obtained in 1644 by Evangelista Torricelli (1608-1647) and Vincenzo Viviani (1622-1703) - students of the brilliant Italian scientist Galileo Galilei. E. Torricelli soldered a long glass tube with divisions from one end, filled it with mercury and lowered it into a cup with mercury (this is how the first mercury barometer was invented, which was called the Torricelli tube). The level of mercury in the tube dropped as some of the mercury spilled into the cup and settled at 760 millimeters. A void formed above the column of mercury, which was called the Torricelli void. E. Torricelli believed that the pressure of the atmosphere on the surface of the mercury in the cup is balanced by the weight of the mercury column in the tube. The height of this column above sea level is 760 mm Hg. Art.
Slide 19
Slide 20
Conclusion:
Torricelli noticed that the height of the mercury column in the tube changes, and these changes in atmospheric pressure are somehow related to the weather. If you attach a vertical scale to a tube with mercury, you get the simplest barometer.
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WHAT WOULD HAPPEN ON EARTH if the air atmosphere suddenly disappeared?
slide 22
On Earth, a temperature of approximately -170 ° C would be established, all water spaces would freeze, and the land would be covered with an ice crust. - there would be complete silence, since sound does not propagate in the void; the sky would become black, since the color of the firmament depends on the air; there would be no twilight, dawns, white nights. - the twinkling of the stars would stop, and the stars themselves would be visible not only at night, but also during the day (we do not see them during the day due to the scattering of sunlight by air particles). - Animals and plants would die. ...some planets solar system also have atmospheres, but their pressure does not allow a person to be there without a space suit. On Venus, for example, atmospheric pressure is about 100 atm, on Mars - about 0.006 atm. Due to the pressure of the atmosphere, a force of 10 N acts on each square centimeter of our body.
Atmospheric pressure - the pressure of atmospheric air on objects in it and on the earth's surface. At each point in the atmosphere, atmospheric pressure is equal to the weight of the overlying column of air with a base equal to unit area. Atmospheric pressure decreases with height.
HOW DO WE DRINK? The inhalation of liquid by the mouth causes expansion of the chest and rarefaction of air both in the lungs and in the mouth. The external atmospheric pressure, increased compared to the internal one, "drives" part of the liquid there. This is how the human body uses atmospheric pressure.
A person cannot easily walk in a swamp? Why? The fact is that when you raise your leg, a rarefied space forms under it. The preponderance of atmospheric pressure in this case can reach H per foot area of an adult.
WHO IS EASIER TO WALK IN THE MUD? Artiodactyl animals pull their hooves out of the quagmire without difficulty. What's the matter? It's about the structure of the hoof. It is not continuous, but consists of two parts. When pulling the foot out of the swamp, air is passed into the resulting rarefied space. The pressure from above and below the hoof equalizes, and the leg is taken out without much difficulty.
How does an elephant drink? An elephant uses atmospheric pressure whenever it wants to drink. His neck is short, and he cannot bend his head into the water, but lowers only his trunk and draws in air. Under the influence of atmospheric pressure, the trunk is filled with water, then the elephant bends it and pours water into its mouth.
Conclusions. Atmospheric pressure has a huge impact on everything on Earth. If the atmosphere disappeared, then: the temperature on Earth would be approximately -170 ° C, all water spaces would freeze, and the land would be covered with an ice crust. - there would be complete silence, since sound does not propagate in the void; the sky would become black, since the color of the firmament depends on the air; there would be no twilight, dawns, white nights. - the twinkling of the stars would stop, and the stars themselves would be visible not only at night, but also during the day (during the day we do not see them due to the scattering of sunlight by air particles). - Animals and plants would die.
slide 1
Atmosphere pressure. Wind.
slide 2
High pressure Low pressure
How high and low atmospheric pressure is formed.
An area of high atmospheric pressure is formed by descending air currents. Molecules of atmospheric gases in this case have more low temperature. And they go down to the Earth. Thus, a denser air layer is created near the Earth's surface, which "presses" on the Earth's surface more than others. air masses in the surrounding areas.
The formation of a low pressure area, on the contrary, is associated with ascending air currents.
Cold air near the surface of the Earth cannot accumulate in one place. It begins to move into an area of low pressure.
slide 3
WIND is the movement of air from areas of high pressure to areas of low pressure.
slide 4
West East North South Southwest Northeast Northwest Southeast
Wind directions
slide 5
Rose of Wind.
slide 6
How to measure atmospheric pressure?
For the first time, the weight of the air confused people in 1638, 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 search for the causes of the stubbornness of water and experiments with a heavier liquid - mercury, undertaken in 1643. Torricelli, led to the discovery of atmospheric pressure.
Slide 7
mercury barometer
Inverted tube height = 1 m
1 m = 1000 mm
At high atmospheric pressure, the air strongly presses on the surface of the mercury in the lower tank ....
Mercury is forced by air pressure to fill the tube and the mercury column inside the glass tube rises higher. The number of millimeters (number) increases ... Pressure - "grows".
Slide 8
The receiving part is a round metal box A with corrugated bases, inside which is very rarefied air. When atmospheric pressure rises, the box compresses and pulls the spring attached to it; when the pressure decreases, the spring unbends and the upper base of the box rises. The movement of the end of the spring is transmitted to the arrow B, moving along the scale C.
Barometer - aneroid.
Slide 9
1648 - Pascal's experience on Mount Puy de Dome. Pascal 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, because. are in continuous thermal motion.
Slide 10
Change in pressure with height.
At low altitudes, every 10–11 m of ascent reduces atmospheric pressure by 1 mm Hg. At high altitudes, this pattern is violated.
slide 11
Atmospheric pressure belts on Earth.
Without the influence of the deflecting force of the Earth's rotation around its axis.
Taking into account the influence of the deflecting force of the Earth's rotation around its axis.
slide 12
Breeze Day Night
Constant winds formed in the coastal part due to the change in water and land temperatures during the day and at night.
slide 13
day Night
Slide 14
Wind speed depends on atmospheric pressure.
The greater the difference in pressure between areas of the earth's surface, the greater the force of the wind. Wind speed is measured in meters per second (m/s).
