Does air have weight? Does air have the weight of Air and not much weight?

When we want to emphasize the lightness, almost “weightlessness” of something, we usually say “airy,” thereby emphasizing that air appears to us as something that has no weight. People were confident of this for many centuries, and their confidence was reinforced by the authority of such a respected scientist as Aristotle. This great ancient Greek philosopher once wondered whether air has weight. As befits a scientist, he decided to test this in an experiment. He placed a leather wineskin inflated with air on one pan of the scales, and on the other - exactly the same wineskin, only empty. The scales have balanced, therefore air weighs nothing!

Let's not judge strictly: at that time physics was just in its infancy, and Aristotle, like any pioneer, could not avoid mistakes. To understand what the great scientist’s mistake was, let’s remember exact value words "weight": the force with which the body acts on a support or suspension. What we call weight in everyday life and measure in kilograms is mass, the property of bodies to change their speed when a force is applied to them. There is no need to confuse these concepts: in zero gravity, bodies lose precisely weight, not mass, so in spaceship the cabinet will hang in the air, but moving it from its place will be no easier than on Earth. So, with the help of scales they measure precisely weight, but this weight corresponds to a certain mass, and since it is mass that interests us, for simplicity we are talking about grams and kilograms, and not about newtons, in which force is measured, but is measured - it was precisely force, and it was precisely with force that the error came out. When a leather wineskin was inflated, its volume increased, therefore, the buoyant force of the surrounding air acting on it changed (Archimedes' law, which had not yet been discovered in Aristotle's time), so the scales balanced.

G. Galileo took a different path. He was not weighing a bag, but a hollow copper ball, which cannot change its volume. The researcher placed it on a scale and then pumped the air out of the ball. So what? The ball has become lighter! This meant that the “weightless” air had weight!

At that time, such a statement could look extremely bold (it’s no joke to argue with Aristotle himself, whose views were “sanctified” by the authority catholic church!), but now we understand that this is logical. In order for a body to have weight (i.e., to act on a support), it needs, in essence, a little - for the force of gravity to act on it. It affects the air. If this were not so, we would not have an atmosphere left, all the atoms of the gases that make it up would scatter in outer space, therefore, the air also has a weight that acts on the earth’s surface and on everything that is on it. This weight is really small - a thimble of water, for example, weighs more than a liter of air, but... there is a lot of it! If we take air from earth's surface to the upper boundary of the atmosphere over an area of \u200b\u200bone square centimeter - this will be a weight corresponding to one kilogram. The area of the human palm is about 70 square centimeters, therefore, the air has the same effect on it as if we were holding an object weighing 70 kg in our palm! And on the human body as a whole, air acts with a force corresponding to 15 tons, that’s three five-ton trucks!

But we don’t feel this heaviness for one simple reason: there is also air inside our body, and it acts with the same force, balancing the weight of the air outside. It cannot be otherwise, because our biological species arose on this planet, in the conditions of this atmosphere. But the atmosphere of Venus, for example, would crush us in no time!

Although we cannot feel the air around us, air is not nothing. Air is a mixture of gases: nitrogen, oxygen and others. And gases, like other substances, consist of molecules, and therefore have weight, although small.

Experiments can be used to prove that air has weight. In the middle of a stick about sixty centimeters long, we will strengthen a rope, and tie two identical ones to both ends balloon. Let's hang the stick by a string and see that it hangs horizontally. If you now pierce one of the inflated balloons with a needle, the air will come out of it, and the end of the stick to which it was tied will rise up. If you pierce the second ball, the stick will again take a horizontal position.

This happens because there is air in the inflated balloon. tighter, and therefore heavier than the one around it.

How much air weighs depends on when and where it is weighed. The weight of air above a horizontal plane is atmospheric pressure. Like all objects around us, air is also subject to gravity. It is this that gives the air a weight that is equal to 1 kg per square centimeter. The density of air is about 1.2 kg/m 3, that is, a cube with a side of 1 m filled with air weighs 1.2 kg.

A column of air rising vertically above the Earth stretches for several hundred kilometers. This means that a column of air weighing about 250 kg presses on a person standing upright, on his head and shoulders, the area of which is approximately 250 cm 2!

We would not be able to withstand such a weight if it were not resisted by the same pressure inside our body. The following experience will help us understand this. If you stretch a sheet of paper with both hands and someone presses a finger on it on one side, the result will be the same - a hole in the paper. But if you press two index fingers nothing will happen to the same place, but from different sides. The pressure on both sides will be the same. The same thing happens with the pressure of the air column and the counter pressure inside our body: they are equal.

Air has weight and presses on our body from all sides.
But it cannot crush us, because the counter pressure of the body is equal to the external one.
The simple experiment depicted above makes this obvious:
if you press your finger on a sheet of paper on one side, it will tear;
but if you press on it from both sides, this will not happen.

By the way...

In everyday life, when we weigh something, we do it in the air, and therefore we neglect its weight, since the weight of air in air is zero. For example, if we weigh an empty glass flask, we will consider the result obtained to be the weight of the flask, neglecting the fact that it is filled with air. But if the flask is sealed and all the air is pumped out of it, we will get a completely different result...

Melnikova Valeria

Research work on the surrounding world

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City scientific and practical conference

"Planet of Erudites"

Does air have weight?

The world around us

Melnikova Valeria Igorevna,

4 “A” class, MBOU secondary school No. 14

Supervisor:

Mikhailova I.R.,

teacher primary classes, MBOU secondary school No. 14

Dzerzhinsk

2013

Air purification.
Air has weight.
Conducting experiments.

Introduction

Our entire planet is shrouded in a transparent blanket - air. We don't see it, we don't feel it. But if it suddenly disappears, water and all other liquids on Earth will instantly boil, and the rays of the Sun will burn all living things.

A person can live without food for five weeks, without water for five days, and without air for at most five minutes. Humans, animals and plants need air to breathe, and therefore to live. What about the wind? After all, this is air movement! Without wind, clouds would always be above the sea or river. This means that rain without wind could only fall over water. Under the influence of air and water they occur geological processes On the surface of the Earth, weather and climate are formed. By burning fuel (and oxygen must participate in this - component air), people have long received the heat they need both at home and at work.

Air is the most important source of chemical raw materials. Just two centuries ago, scientists learned that air is a mixture of many gases, mainly oxygen and nitrogen, argon and carbon dioxide. Due to the relevance of this problem, we have identified the followingpurpose of the study:Determine if air has weight?

Research objectives:

Analyze best practices regarding the study of air;
Determine the properties of air;
Conduct an experiment to determine the weight of air;
Draw conclusions.

The meaning of air for humans.

For man great value have temperature, humidity, air movement. For example, if you are lightly dressed and doing simple work, best temperature air 18-20 C. The harder the work, the lower the air temperature can be, but not so much that it becomes difficult to breathe, as with severe frost. People feel best when the air humidity is 40-60 percent. Usually dry air is well tolerated, but high air humidity has an unfavorable effect: when high temperature the body overheats; when it is low, it becomes hypothermic.

Air purification.

The amount of carbon dioxide in the air is increasing, chemical compounds that are thrown away industrial enterprises and cars.

There is a widespread movement in the world to protect nature. We have adopted laws and are developing new ones, according to which enterprise managers are responsible for cleaning and neutralizing gases before they are released into the atmosphere.

Plants, the lungs of the planet, play a huge role in air purification. They trap dust, soot, absorb carbon dioxide and release oxygen. Among other natural filters, poplar and sunflower are the best at purifying air from pollution. Studies have shown that on busy highways lined with pyramidal poplars and sunflower fields, the air remained clean.

Air has weight.

Air has weight. A liter bottle, for example, contains more than one gram of air. With its weight, the air presses on us and on all objects around us. If, for example, you pump out air from a tin can, it will flatten.

At a temperature of 0 °C and normal atmospheric pressure, the mass of air with a volume of 1 m3 is 1.29 kg.

Conducting experiments.

Experiments can be used to prove that air has weight. In the middle of a stick about sixty centimeters long, we will attach a rope, and we will tie two identical balloons to both ends. Let's hang the stick by a string and see that it hangs horizontally. If you now pierce one of the inflated balloons with a needle, the air will come out of it, and the end of the stick to which it was tied will rise up. If you pierce the second ball, the stick will again take a horizontal position.

This happens because the air in the inflated balloon is denser, and therefore heavier, than the air around it.

Another experience:

Take an empty transparent one plastic bottle. This experience will show whether it is as empty as it seems. Place the bottle in a bowl of water until it begins to fill. Look what happens to the water. You see bubbles coming out of the neck. This water displaces the air from the bottle. Most objects that appear empty are actually filled with air.

Feel the air.

Is there air around? It's very easy to find out. Wave a piece of cardboard in front of your face. The cardboard will make the air move and you will feel its breath on your face.

Paper races.

Air can move objects. We propose to arrange the following game: each player will need a cardboard and a sheet of paper. One side of the sheet needs to be folded back. Instead of finishing tape, use string. Now, on command, wave the cardboards behind the sheets of paper, and the air will move them forward.

Heavy newspaper.

Take half a sheet of newspaper and spread it on the table. Place a ruler under the newspaper so that its end protrudes beyond the edge of the table. Press the ruler and try to tear it off the table.

It turns out that this is not so easy to do, because the air pressure presses the newspaper to the table.

Flattened package.

To experiment, take a small juice bag with a hole for the pipe. Suck the juice from the bag through a straw. Keep drawing air through it. See what happens. When some of the air leaves the bag, outside air will squeeze its walls. Take out the straw and look at the bag.

The walls parted again because air entered the bag and straightened it. See what happens to the bag if you blow even more air into it.

Thus, we have proven that air has weight.

Conclusion.

How much air weighs depends on when and where it is weighed. The weight of air above a horizontal plane is atmospheric pressure. Like all objects around us, air is also subject to gravity. It is this that gives the air a weight that is equal to 1 kg per square centimeter. The density of air is about 1.2 kg/m3, that is, a cube with a side of 1 m filled with air weighs 1.2 kg.

By the way...

References

Yu.V. Novikov “Ecology” environment and man"
Encyclopedia "The World Around Us"
Website http://www.5.km.ru/

Physics at every step Perelman Yakov Isidorovich

How much does the air in the room weigh?

Can you say at least approximately how much weight the air contained in your room represents? A few grams or a few kilograms? Are you able to lift such a load with one finger, or would you barely be able to hold it on your shoulders?

Now, perhaps, there are no longer people who think, as the ancients believed, that air weighs nothing at all. But even now many people will not be able to say how much a certain volume of air weighs.

Remember that a liter mug of air of the density it has near the earth’s surface at ordinary room temperature weighs about 1.2 g. Since a cubic meter contains 1 thousand liters, a cubic meter of air weighs a thousand times more than 1.2 g, namely 1.2 kg. Now it is not difficult to answer the question posed earlier. To do this, you just need to find out how much cubic meters in your room, and then the weight of the air contained in it will be determined.

Let the room have an area of 10 m2 and a height of 4 m. In such a room there are 40 cubic meters of air, which weighs forty times 1.2 kg. This will be 48 kg.

So, even in such a small room, the air weighs a little less than you. You would be able to carry such a load on your shoulders with difficulty. And the air of a room twice as spacious, loaded onto your back, could crush you.

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Anna Oreshkina
Lesson summary “Does air have weight”

Target: formation of a holistic perception of the surrounding world, development of interest in children’s research and cognitive activities.

Tasks:

Contribute to the enrichment and consolidation of children’s knowledge about the properties air, expanding children’s understanding of the importance air in human life, animals, plants; develop in children the ability to establish cause-and-effect relationships based on a basic experiment and draw conclusions; cultivate interest in research activities.

Progress of the lesson:

Educator: Let's say hello to everyone.

(Communication game)

Let's stand next to each other,

Let's say "Hello!" to each other.

We are not too lazy to say hello:

Everyone "Hello!" And "Good afternoon!"

If everyone smiles -

Good morning will begin.

GOOD MORNING!

Educator: Guys, tell me, what surrounds us? Children: Houses, trees, birds, animals.

Educator: Right!

Educator: Guys, today we will learn something very interesting. We have a new task, it’s in this beautiful box. Do you want to know what's inside her? (opens the box, it is empty)

Children: The box is empty, there is nothing in it.

Educator: I don’t agree with you, it’s not empty, there’s something in it, but what, you’ll find out if you guess riddle:

Passes through the nose into the chest,

And the return is on its way.

He's invisible, but still

We cannot live without him.

We need him to breathe

To inflate the balloon.

With us every hour,

But he is invisible to us!

Children: Air!

Educator: That's right, that's air!

Air man: Oh, help, save me, I’m flying!

Educator: Who is that screaming there?

(flies into the room Air little man - made of blue balls).

Educator: Hello, Air man! How did you come to us?

Air man: Hello guys! I was walking, but suddenly the wind picked me up and carried me, carried me and brought me to you in kindergarten. How interesting you are here! What are you doing here? Can I stay?

Educator: Of course, stay. Today the guys and I are talking about air. Air man: ABOUT air? What is it air? I heard something about him, but never met him. Maybe he doesn't exist at all?

Educator: Wait, Air man, I know that the air around us.

Air man: I don't see anything. Where is he? Where did he hide?

Educator: He didn’t hide anywhere. Guys, let's prove it To the air man that air really exists. Stay tuned Air man, and you will understand everything yourself!

Air man: Okay, guys! I'll stay!

Educator: Guys, today we will talk about air like real research scientists. Scientists work in a room where there are many instruments for experiments, but what is this room called?

Children: Laboratory.

Educator: In the laboratory it is necessary to observe certain rules. Which? Children: Maintain silence, do not interrupt each other, do not disturb each other, work quietly, carefully, carefully.

Educator: Let's go to our laboratory to conduct experiments (walk in a circle, then go to the tables).

To become nature's friend,

Find out all her secrets,

Solve all the riddles

Learn to observe

Let's develop together

Quality - care,

And it will help you find out everything

Our powers of observation.

Educator: So we found ourselves in a scientific laboratory. And for greater mystery, I hid all the devices in boxes.

We are starting experiments

It's interesting here

Try to understand everything

There's a lot to learn here

Educator: Guys, do you know that a person can live without food - 30 days, without water - 15 days, and without air can't live even 5 minutes. Let's check it out.

Experiment "DELAY AIR»

Educator: Let's breathe in more air, hold your nose with your hand and "let's dive", and as soon as the air will run out, That "let's emerge" (checks with an hourglass)

Conclusion: a person cannot live without air.

Experiment "WEIGHT AIR»

(Laid out on the table items: rubber toy, piece of rubber). Educator: Let's put a piece of rubber and a rubber toy on the scale. What

heavier? That's right, a rubber toy. Educator: Let's take a piece of rubber and put it in the water. What happened to him? (He drowned). Now let’s lower the rubber toy into the water. What happened to her? (She doesn't drown). Why? After all, a toy is heavier than a piece of rubber? What's inside the toy? (Air)

Conclusion: air has weight, but it is lighter than water.

Experiment « Does air have weight??»

Educator: Guys, all objects around us have weight. How do you think, does air have weight? (answers)

We'll check this now.

Educator: For the next experiment, let's take two identical air ball and put them on the scales.

What do we see? (the scales are motionless)

Now put the inflated balloon on one bowl. What did you notice? Why? (answers)

Conclusion: Air has weight.

Educator: So, today we conducted many experiments. Tell me, did you enjoy conducting the experiments? (children's answers). What experience did you find most interesting? (children's answers). What new did you learn today? (children's answers).

Educator: Oh, guys, do you hear, he’s calling us? Air man?

Air man: Guys, tell me, did I understand everything correctly or not?

Educator: So we’ll check it now. I suggest you take 2 mugs from the table. One red and one green. Instead of responding to statements Air little man you will show the mugs. If you agree, raise a green circle; if you disagree, raise a red one. Let's try it. Be careful!

Air surrounds us on all sides.

The air can be heard.

The air is clear, so we don't see it.

Clean the air has no smell, but can transmit the smell of objects.

A person can live without air.

Wind is movement air. Air is heavier than water.

Air man: Well done, guys! As a gift I want to give you an item with air. This balloon!

Children: Thank you!

Application

Poem about air

He is transparent and invisible,

Light and colorless gas.

He envelops us with a weightless scarf.

It is thick and fragrant in the forest,

Like a healing infusion.

Smells of resinous freshness,

Smells of oak and pine.

In summer it is warm,

It blows cold in winter.

When the frost lay on the glass

Lush white fringe.

We don't notice him

We don't talk about him.

We just breathe it in -

We need him.

MESSAGE ABOUT IN THE AIR

Air- This is an amazing shell around our Earth. If it weren't for air, all living things died in the scorching rays of the Sun during the day, and at night from the cold. Wind is movement air. He distills the cold air to the south, warm to the north, disperses clouds or collects them in rain clouds. Without air The earth would be a dead desert. Not in space air, so the astronauts stock up by air from Earth. Air necessary for all creatures on Earth to breathe and live. We breathe in the air is clean, and we exhale - bad. Plants, on the contrary, inhale bad leaves and exhale good leaves. They cleanse air. The wind helps plants: blows dust from leaves, spreads plant seeds throughout the Earth. Air- This inanimate nature, but it is closely related to living nature.

Literature:

1. Tugusheva G. P., Experimental activities children of middle and senior preschool age.

2. Dybina O. V. Unknown near: Entertaining experiments and experiments for preschoolers. - M.: TC Sfera, 2005.

3. Dybina O. V. Child and the world around us. Program and methodological recommendations. - M.: Mosaic-Sintez, 2006

4. Zenina T. Environmental actions in working with preschoolers. // Preschool education. - 2002. - No. 7. - p. 18.

Municipal autonomous preschool educational institution

General developmental kindergarten No. 12

Municipal entity

Novorossiysk

Abstract in the preparatory group

On the topic: « Does air have weight?»

Prepared and carried out:

A. V. Oreshkina

Novorossiysk 2017