Can air hold liquid when evacuated. What is air pressure

Since the air pressure at altitude is less than at sea level, the air there is less dense, rarefied. With each breath in your lungs, there is less oxygen, namely its molecules, than when breathing in a lowland, closer to sea level. At the same time, the oxygen content (its percentage) in the air does not change.

This means that in such conditions it is more difficult for the human body to absorb the amount of oxygen it needs than when it is at sea level. When the body's need for oxygen exceeds the ability to absorb it from rarefied air (this can happen with significant physical exertion), hypoxia develops - oxygen deficiency. The reason for the appearance of hypoxia even before the start of the descent from the mountain is often the heavy physical exertion that the rider experiences during the ascent. Signs and symptoms of hypoxia include fatigue, dizziness, weakness, and total loss of energy. It seems to you that the work you are doing is much more difficult than usual.

Fortunately, hypoxia is easy to avoid. Being high above sea level, you need to limit your physical activity and rest more often. Take extra time to pack, don't take more than you need, and remember that in the mountains, every kilogram costs three. Make sure you don't get short of breath. If you live high above sea level, or spend a lot of time in the mountains, then your body, accustomed to rarefied air, is less susceptible to hypoxia.

The state of hypoxia can come unexpectedly, in the final phase of your physical exercises. In the lowlands, your body is affected by atmospheric pressure to a greater extent than in the mountains, and your body easily receives the oxygen it needs. In the mountains, in a rarefied atmosphere, after heavy physical exertion, it is difficult to restore your breathing.

Feeling signs of hypoxia, immediately stop making any physical effort, take a break and restore breathing. Resume activity only after breathing returns to normal, and do everything at a slower pace. If you are a little tired doing physical exercises, rest and restore your breath before the next uphill.

The intensity of the development of mountain sickness depending on the height:

1000-2500 Physically untrained people experience some lethargy, slight dizziness, palpitations. But there are no symptoms of altitude sickness yet.

2500-3000 Most physically healthy people will already feel the effect of altitude and rarefied air. There will be a headache, pain in muscles and joints is possible, loss of appetite, respiratory rhythm disturbances, drowsiness are possible. But there will most likely not be pronounced symptoms of mountain sickness. But some untrained or weakened people may experience deviations in behavior. High spirits, excessive gesticulation and talkativeness, causeless fun and laughter. Very similar to a little alcohol intoxication.

4000-5000 Maybe she will show up here. Mountain sickness. In its most unpleasant symptoms. Acute and severe mountain sickness in some cases may occur. A sharp deterioration in breathing, a violation of the rhythm of respiratory movements, complaints of suffocation. Frequent nausea and vomiting, pain in the abdomen. The excited state is replaced by apathy, indifference, low mood, melancholy. Pronounced symptoms of altitude sickness may not appear immediately, but after some time at this height.

5000-7000 Feeling of general fatigue, loss of strength, heaviness in the whole body. Pain in the temples. With sudden movements - dizziness. Lips acquire a blue-purple hue, body temperature rises. There may be bleeding from the nose and lungs. And sometimes stomach bleeding. There are hallucinations.

Altitude sickness is best overcome by acclimatization. Before the onset of the illness. Acclimatize in advance. Eat more vitamins and carbohydrates. The most important condition here is the complete rejection of the use of alcohol and nicotine.

In the event of an attack, first aid, as mentioned above, is the cessation of all physical exertion, in case of fainting, artificial respiration, rest.

Prevention of mountain sickness, we repeat - acclimatization. Take a break and rest. Let the body itself get used to this height, adapt to new conditions. But in very severe cases, an immediate descent into the valley is recommended. The mountain sickness will go away on its own. Preventive agents are: caffeine - 0.1 gr., Pyramidone - 0.3 gr., enhanced nutrition, vitamins, glucose with vitamin C.

Using Russian translation, Adventures in Diving PADI textbook and 1000+1 travel tips

What is rarefied air? Explain to me like a fool what rarefied air is ...

1. So the guys want to reassure everyone ... First of all, the molecules are not getting smaller! they simply move away from each other… It follows that the concentration of gases does not change, the volume of the gas mixture system changes! And this happens due to a decrease in pressure ... The gas mixture is like a spring, the more you squeeze it, the less volume it will eventually occupy ... The lower the potential pressure, the greater the volume! With the same concentration but a larger volume, our body must ventilate more air, but since the volume of the lungs has its maximum, and is unable to take in more, we experience malaise (hypoxia)
2. Now, if air is imagined as water, then in a liter jar there will be less than a liter and nothing else will be ... drops of water seem to recede from each other.
   So it is with air
3. You climb a high mountain and oops! And there is nothing to breathe))
   In general, this is low atmospheric pressure, observed at high altitudes.
4. 
   
   Hence the meaning of the word "rarefied" - air. in which molecules are located less often. Because there are just fewer of them.

   I saw. How do you pump up a ball? Air is pumped into it, there are more air molecules there, and since they always move randomly, they now more often hit the walls of the ball from the inside and put pressure on it. Therefore, the inflated ball is so elastic.
   Now imagine that the pump works in the opposite direction - it pumps out air. Of course, the ball will simply flatten - that's all. But if instead of a ball we have a rigid vessel - glass, metal, then it retains its shape and dimensions. But the air (and molecules) when pumping out in it becomes really less. This is what is called rarefied air.

   So rarefied air is obtained artificially. But it also happens in nature. Namely:
   the higher you climb from sea level into the mountains, the thinner the air becomes. Therefore, it is difficult to breathe high in the mountains, climbers even put on oxygen masks. And even higher, where planes fly, the air is even more rarefied. And if the sealing of the aircraft is broken, the passengers will die very quickly. You ask: why do planes climb so high if it's dangerous? Hard economic interests are forcing this: rarefied air is much less dense than below, and therefore offers less resistance. This means that the aircraft can fly at a higher speed, the flight time is reduced, and fuel is saved.

   PS Isn't it time to take a break from physics? . Look at my page (in My world), look through photo albums ...

5. Anatoly Shodoev Enlightened (48195) 5 years ago
   First of all, I'm not going to explain like a fool. I will explain as a normal student who did not understand the topic a little.
   Secondly, well done. that you spell the word sparse correctly. So many people write discharge, maybe they even think that this word comes from the word "discharge".
   In fact. of course, the word "rarely" is at the heart of it.
   ======================================================
   And how to understand then how to defuse the AK 47 assault rifle? If this word is based on "rarely"?
6. There is such a thing as pressure. imagine that there is a certain amount of air in the piston, we pull the piston, and now the previous volume has doubled, and there is as much air left as it was before. this will be rarefied air, as opposed to, for example, the pressure of excess air in the tires of a car. And don't call yourself a fool, that's bad
7. “But how to understand then how to defuse the AK 47 assault rifle? If this word is based on “rarely”?
   Sparse comes from the word rarely.
   And discharge comes from the word discharge.

Mountains attract people with their beauty and grandeur. Ancient, like eternity itself, beautiful, mysterious, bewitching the mind and heart, they do not leave anyone indifferent. Breathtaking views of mountain peaks covered with never-melting snow, slopes covered with forests, alpine meadows are pulling back everyone who has spent a vacation in the mountains at least once.

It has long been observed that people in the mountains live longer than in the plains. Many of them, living to a ripe old age, retain good spirits and clarity of mind. They get sick less and recover faster after illnesses. Women of the middle mountains retain the ability to bear children much longer than women of the plains.

Breathtaking views of the mountains are complemented by the purest air, which is so pleasant to breathe in deeply. Mountain air clean and filled with aromas of healing herbs and flowers. It does not contain dust, industrial soot and exhaust gases. They breathe easily and it seems that you can not breathe in any way.

Mountains attract a person not only with their beauty and grandeur, but also with a steady improvement in well-being, a noticeable increase in efficiency, a surge of strength and energy. In the mountains, the air pressure is less than in the plains. At an altitude of 4 kilometers, the pressure is 460 mmHg, and at an altitude of 6 km - 350 mmHg. With an increase in altitude, the air density decreases, and the amount of oxygen in the inhaled volume decreases accordingly, but paradoxically, this has a positive effect on human health.

Oxygen oxidizes our body, contributes to aging and the occurrence of a host of diseases. At the same time, without it, life is impossible. Therefore, if we want to significantly extend life, we need to achieve a reduction in the flow of oxygen into the body, but not too little and not too much. In the first case, there will be no therapeutic effect, and in the second case, you can harm yourself. Such a golden mean is the mountain air of the middle mountains: 1200 - 1500 meters above sea level, where the oxygen content is approximately 10%.

At present, it has already been clearly established that there is only one factor that prolongs a person's life in the mountains - this is mountain air, the oxygen content of which is lowered and this has an extremely beneficial effect on the body.

The lack of oxygen causes a restructuring in the work of various body systems (cardiovascular, respiratory, nervous), causes reserve forces to turn on. This, as it turned out, is a very effective, inexpensive, and most importantly affordable way for everyone to restore and improve health. When the amount of oxygen in the inhaled air decreases, a signal about this is transmitted through special receptors to the respiratory center of the medulla oblongata, and from there it goes to the muscles. The work of the chest and lungs intensifies, the person begins to breathe more often, respectively, the ventilation of the lungs and the delivery of oxygen to the blood improve. There is an increase in heart rate, which increases blood circulation, and oxygen reaches the tissues faster. This is facilitated by the release of new erythrocytes into the blood, and, consequently, the hemoglobin contained in them.

This explains the beneficial effect of mountain air on a person's vitality. Coming to the mountain resorts, many notice that their mood improves, their vitality is activated.

But if you climb higher into the mountains, where the mountain air contains even less oxygen, the body will react to its lack in a completely different way. Hypoxia (lack of oxygen) will already be dangerous, and the nervous system will suffer first of all, and if oxygen is not enough to maintain the brain, a person may lose consciousness.

In the mountains, solar radiation is much stronger. This is due to the high transparency of air, since its density, the content of dust and water vapor in it decreases with height. Solar radiation kills many harmful airborne microorganisms and decomposes organic matter. But most importantly, solar radiation ionizes the mountain air, contributing to the formation of ions, including negative oxygen and ozone ions.

For the normal functioning of our body in the air we breathe, both negatively and positively charged ions must be present, and in a strictly defined ratio. Violation of this balance in any direction has a very adverse effect on our well-being and health. At the same time, negatively charged ions, according to modern scientific data, are necessary for a person as well as vitamins in food.

In rural air, the concentration of ions of both charges on a sunny day reaches 800-1000 per 1 cubic cm. In some mountain resorts, their concentration rises to several thousand. Therefore, the mountain air has a healing effect on most living beings. Many of the centenarians of Russia live in the mountains. Another effect of rarefied air is an increase in the body's resistance to the damaging effects of radiation. However, at high altitudes, the proportion of ultraviolet radiation sharply increases. The impact of ultraviolet rays on the human body is very high. Possible skin burns. They damage the retina of the eye, causing severe pain and sometimes temporary blindness. To protect the eyes, it is necessary to use goggles with light-protective glasses, and to protect the face, wear a hat with wide brim.

Recently, such methods as orotherapy (treatment with mountain air) or normobaric hypoxic therapy (treatment with rarefied air with a low oxygen content) have become widespread in medicine. It is well established that with the help of mountain air it is possible to prevent and treat the following diseases: occupational diseases associated with lesions of the upper respiratory tract, various forms of allergic and immunodeficiency conditions, bronchial asthma, a wide group of diseases of the nervous system, diseases of the musculoskeletal system, diseases cardiovascular system, diseases of the gastrointestinal tract, skin diseases. Hypoxic therapy excludes side effects as a drug-free method of treatment.

The amount of oxygen and nitrogen sharply decreases with height. It's all about the pressure difference between the upper and lower layers of the atmosphere. The upper layers put a lot of pressure on the lower ones, so there is much more air in the latter and its pressure is lower. Climbers, climbing to great heights, experience some difficulties.

It all depends on the height at which the person is located. If it does not exceed 1 km, the difference is almost imperceptible, and there will be no harm to the body. An altitude of 1 to 3 km also cannot harm a healthy person (the body easily compensates for the lack of oxygen). Sick people, especially those who suffer from asthma, should not go on such a dangerous journey.

At an altitude of 5 to 6 km, the body of a healthy person mobilizes all systems and makes them work in an enhanced mode due to a lack of oxygen. A trained person copes with such a height, so various research bases and observatories are often located here. Healthy sleep and proper nutrition help the body of scientists to cope with a stressful situation.

Places located at an altitude of 7 km and above are unsuitable for human life. There is so little oxygen here that the blood cannot fully deliver it to all organs. They begin to experience oxygen starvation. A person feels tired, headache, general condition worsens. At an altitude of 8 km and above, a person can spend no more than 3 days.

Life in the mountains

Mountain dwellers are much healthier and live longer than plain dwellers. What explains this? Oxygen is by nature a strong oxidizing agent. Any oxidizing agent in the body, to a greater or lesser extent, causes its aging. But a person cannot live. To improve health, you need a slightly lower oxygen content in the air than on the plains.

The optimal height for a comfortable life is about 1500 meters above sea level. The body experiences a slight oxygen starvation, which includes all systems in an enhanced mode. Improves blood circulation and ventilation of the lungs, increases the level of hemoglobin in the blood.

American scientists have noticed that people living in the mountains are characterized by guttural sounds in speech. At high altitude, it is much easier to make such sounds, since for this you need to compress the air in the throat. This is easiest to do precisely in the highlands, since the air here is thinner than on the plains.

Air density is not the same. Where it is smaller, the air is rarefied. Let's find out what rarefied air means and what features it is characterized by.

Gaseous shell of the Earth

Air is an intangible, but extremely important component of our planet. It participates in the process of energy exchange, supporting all the vital functions of organisms. It promotes the transmission of sounds, prevents the Earth from hypothermia and protects it from the excessive influence of solar radiation.

Air is the outer shell of the planet, called the atmosphere. It consists of many gases: neon, argon, hydrogen, methane, helium, krypton, etc. The main share is oxygen and nitrogen, which make up from 98% to 99% of air.

The ratio of gases and their quantity may vary. So, because of exhausts of cars and emissions of factories, urban air is more saturated with carbon dioxide. In forests, in areas where there are no industries, the amount of oxygen increases. But in the pasture area, the proportion of methane that cows emit during digestion is growing.

Air density

The density of the gaseous envelope is affected by many factors; it differs in different parts of the planet and at different heights. Air with low density is rarefied air (from the word "rare"). The rarer it is, the farther its molecules are from each other.

Density shows how much air is in one cubic meter of volume. The value of 1.293 kilograms per cubic meter under normal conditions and dry air is chosen as the standard for this value.

In physical science, it is customary to distinguish between specific and mass density. Specific defines, in one cubic meter. It depends on the geographic latitude and inertia from the rotation of the planet. Mass is determined based on barometric pressure, absolute temperature and specific gas constant.

The main patterns of occurrence and principles of rarefied air are described by the law of Gay-Lussac and Boyle-Mariotte. According to them, the higher the temperature and lower the pressure, the rarer the air. At the same time, its humidity is also important: with its increase, the density decreases.

Thin air and altitude

The force of gravity of the Earth, like a magnet, attracts all the bodies available to it to itself. Therefore, we walk, and not chaotically hover in space. Therefore, more molecules of matter are collected at the bottom, which means that its density and pressure are also higher at the earth's surface. The farther away from it, the lower these figures.

Have you noticed that as you climb to great heights, such as in the mountains, it becomes harder to breathe? All because of the rarefied air. With height, the total oxygen content in one liter of air decreases. It does not saturate the blood properly, and we experience difficulty in breathing.

The height of Mount Everest is 8488 meters. At its summit, the air density is one third of the standard density at sea level. A person can notice changes already at an altitude of 1500 to 2500 meters. Further, the change in density and pressure is felt more acutely and already poses a potential health risk.

The most rarefied air is characteristic of the exosphere - the outer layer of the atmosphere. It starts from an altitude of 500-1000 kilometers above. It smoothly passes into outer space, where space is close to a state of vacuum. The pressure and density of gas in space is very low.

Helicopter and rarefied air

A lot depends on the density of the air. For example, it defines a "ceiling" for lifting above the earth's surface. For a person, it is ten thousand meters. But to rise so high, a long preparation is necessary.

Aircraft also have their limits. For helicopters, it is about 6 thousand meters. Much less than airplanes. Everything is explained by the design features and the principles of operation of this "bird".

The helicopter acquires lift with the help of propellers. They spin, dividing the air into two streams: above them and below them. In the upper part, the air moves in the direction of the screws, in the lower part - against. Thus, the density under the wing of the apparatus becomes greater than above it. The helicopter seems to rest on the air below it and takes off.

Rarefied air does not allow you to create the desired pressure. Under such conditions, it will be necessary to greatly increase the engine power and the speed of the propellers, which the materials themselves will not withstand. As a rule, helicopters fly in denser air at altitudes of 3-4 thousand meters. Only once did the pilot Jean Boulet raise his car to 12.5 thousand meters, however, the engine caught fire.