We place a metal bucket on a rotating circle. We drop a small container into it. Then pour liquid for ignition or alcohol into the container. We set fire to the liquid for ignition and begin to rotate the circle. Watching a real tornado.
When the circle unwinds, the flame begins to rise up and twists like a tornado. This happens because when the bucket rotates, it drags the air with it, and a certain vortex is formed inside, that is, a certain movement of air is formed there, and if the air has movement, then the pressure inside will be less according to Bernoulli's law and begins to suck in air from all over. districts. And he also inflates this fire, and since there is an ascending stream, a flame is formed inside, and due to the fact that the stream twists, the air also twists.
Fill the bottle 1/3 hot water. Carefully place the boiled, peeled egg on the neck of the bottle. Wait a few minutes and the egg will fall to the bottom of the bottle. When you pour hot water into a bottle, it and all the air in it heats up. Outside, the air is cooler. And while the air in the bottle and outside is different, hot air tends to leave the bottle as quickly as possible. Due to these actions, a pressure drop occurs, which subsequently causes the testicle to fall to the bottom of the bottle.
3. According to the size of the plywood plank 10x10 cm, cut out a rubber pad from an old volleyball tube and attach it with buttons to the plywood. Pour some water into a half-liter glass jar, and a little alcohol on the water. Ignite the alcohol. After letting it burn for a short time, close the jar with a plank. The fire will go out. After 1-2 seconds, lift the plank. Together with it, a can rises, into which the rubber is drawn. How to explain the lifting of the can with the plank and the retraction of the rubber? Where is this phenomenon used in practice? During combustion, the air heats up. After closing the jar, the combustion process stops. The air starts to cool. A vacuum occurs in the can, due to which it is pressed against the plywood by atmospheric pressure. Rubber retraction is also explained by atmospheric pressure. Treatment with medical cups is based on this phenomenon.
4. EXPERIENCE WITH GLASSES (Magdeburg hemispheres).
Cut out a rubber or paper ring, taking into account the diameter of the faceted glass, and place it on the glass. Light a piece of paper or a small candle on fire, lower it into a glass and close it almost immediately with a second glass. Through. Raise the top glass for 1-2 seconds, followed by the bottom one.
5. Atomizer
Objective: To learn how a spray gun works. You will need a glass, scissors, two flexible straws. 
Pour into a glass of water.
Cut one straw near the corrugated part and place it vertically in a glass so that it comes out 1 cm corrugated from the water.
Position the second straw so that its edge touches the top edge of the straw standing in the water. Use to stop the folds of the corrugation on the vertical straw.
Blow strongly through the horizontal straw.
Water rises along a straw standing in the water and sprayed into the air.
WHY? The faster the air moves, the greater the vacuum created. And since the air from the horizontal straw moves over the upper cut of the vertical straw, the pressure in it also drops. The atmospheric pressure of the air in the room presses on the water in the glass, and the water rises up the straw, from where it is blown out in the form tiny droplets. When you press on the rubber bulb of the spray gun, the same thing happens. The air from the pear passes through the tube, the pressure in it drops, and because of this air rarefaction, the cologne rises and is sprayed.
6. Water does not pour out
7. As soon as the candle stops burning, the water in the glass rises.
Place the coin on a large flat plate. Pour in enough water to cover the coin. Now invite guests or spectators to get a coin without getting their fingers wet. To conduct the experiment, you need another glass and several matches stuck in a cork floating on the water. Light the matches and quickly cover the floating burning boat with a glass without taking any coins. When the matches go out, the glass will fill with white smoke, and then all the water from the plate will automatically collect under it. The coin will stay in place and you can pick it up without getting your fingers wet.
Explanation. The force that drives water under a glass and keeps it there at a certain height is atmospheric pressure. Burning matches heated the air in the glass, its pressure increased, part of the gas came out. When the matches went out, the air cooled again, but when it cooled, its pressure decreased, and water entered under the glass, driven there by the pressure of the outside air.
9. How does it work Diving bell.
Experience 1. Take a plunger, which is used in plumbing, moisten its edges with water and press it against the suitcase, which is placed on the table. Squeeze some of the air out of the plunger and then lift it up. Why does the suitcase rise with him? In the process of pressing the plunger against the suitcase, we reduce the volume occupied by the air, and part of it comes out from under the plunger. When the pressure stops, the plunger expands and a vacuum forms under it. External atmospheric pressure presses the plunger and the suitcase together.
Experience 2. Press the plunger against chalkboard, hang a load of 5-10 kg from it. The plunger is held on the board along with the load. Why?
11. Automatic bird drinker.An automatic bird drinker consists of a bottle filled with water and inverted in the trough so that the neck is slightly below the water level in the trough. Why doesn't water pour out of the bottle? If the water level in the trough drops and the neck of the bottle comes out of the water, some of the water from the bottle will spill out.
12. How we drink. Take two straws, one whole, make a small hole in the second. Through the first, water enters the mouth, through the second it does not. 13. If you pump out air from a funnel, the wide opening of which is covered with a rubber film, then the film is drawn inward, and then even bursts.Inside the funnel, the pressure decreases, under the influence of atmospheric pressure, the film is drawn inward. This is how the following phenomena can be explained: If you put a maple leaf to your lips and quickly draw in air, the leaf will burst with a crack. 
Equipment: rail 50-70 cm long, newspaper, meter.
Conduct: Put a rail on the table, a fully unfolded newspaper on it. If you slowly put pressure on the hanging end of the ruler, then it falls, and the opposite one rises along with the newspaper. If you sharply hit the end of the rail with a meter or hammer, then it breaks, and the opposite end with the newspaper does not even rise. How to explain it?
Explanation: Atmospheric air exerts pressure on the newspaper from above. By slowly pressing the end of the ruler, air penetrates under the newspaper and partially balances the pressure on it. With a sharp blow, due to inertia, air does not have time to instantly penetrate under the newspaper. The air pressure on the newspaper from above is greater than from below, and the rail breaks.
Notes: The rail must be laid so that its end of 10 cm hangs. The newspaper should fit snugly against the rail and the table.
15. Entertaining experiments with atmospheric phenomena
AUTO OSCILLATIONS
Mechanical oscillatory motion is usually studied by considering the behavior of some kind of pendulum: spring, mathematical or physical. Since they are all solid bodies, it is interesting to create a device that demonstrates the vibrations of liquid or gaseous bodies.
To do this, you can use the idea embedded in the design of the water clock. Two one and a half liter bottles are connected in the same way as in a water clock, fastening the lids. The cavities of the bottles are connected with a glass tube 15 centimeters long, with an internal diameter of 4-5 millimeters. The side walls of the bottles should be smooth and non-rigid, easily crushed when squeezed.
To start oscillations, a bottle of water is placed on top. Water from it immediately begins to flow through the tube into the lower bottle. After about a second, the jet spontaneously stops flowing and gives way to a passage in the tube for the oncoming movement of a portion of air from the lower bottle to the upper one. The order of passage of oncoming flows of water and air through the connecting tube is determined by the pressure difference in the upper and lower bottles and is automatically adjusted.
Pressure fluctuations in the system are evidenced by the behavior of the side walls of the upper bottle, which, in time with the release of water and the inlet of air, periodically squeeze and expand. Since the process is self-regulating, this aerohydrodynamic system can be called self-oscillatory.
THERMAL FOUNTAIN
In this experiment, a water jet is shown flying out of a bottle under the action of excess pressure in it. The main part of the fountain design is the jet installed in the bottle cap. The jet is a screw, along the longitudinal axis of which there is a through hole of small diameter. In a pilot plant it is convenient
use a jet from an exhausted gas lighter.
A soft plastic tube is tightly put on the jet at one end, and its other open end is located near the bottom of the bottle. About a third of the volume of the bottle is cool water. The cap on the bottle must be hermetically sealed.
To get a fountain, a bottle is poured from a jug warm water. The air enclosed in the bottle warms up quickly, its pressure rises, and the water is pushed out in the form of a fountain to a height of up to 80 centimeters.
This experience can be used to demonstrate, firstly, the dependence of gas pressure on its temperature, and, secondly, the work done by expanding air to raise water.
ATMOSPHERE PRESSURE
We all constantly stay at the bottom of the ocean of air under the pressure of the gravity of its multi-kilometer thickness. But we do not notice this heaviness, just as we do not think about the need to inhale and exhale this air from time to time.
To show the effect of atmospheric pressure, you need hot water, but not boiling water, so that the bottle is not deformed. One hundred to two hundred grams of such water is poured into a bottle and shaken vigorously several times, thereby warming up the air in the bottle. Then the water is poured out, and the bottle is immediately tightly closed with a lid and placed on the table for viewing.
At the time of corking the bottle, the air pressure in it was the same as the outside atmospheric pressure. Over time, the air in the bottle cools and the pressure inside it drops. The resulting pressure difference on both sides of the bottle walls leads to its squeezing, accompanied by a characteristic crunch
WHAT AIR CAN
Experience 1
He can, for example, toss a coin! Place a small coin on the table and throw it into your hand with a push of air. To do this, holding your hand with a shield behind the coin, sharply blow on the table. Only not to the place where the coin lies, but at a distance of 4-5 cm in front of it.
The air compressed by your breath will penetrate under the coin and toss it straight into your handful.
A few trials - and you will learn how to take a coin from the table without touching it with your hand!
Experience 2
If you have a narrow conical glass, you can do another fun experiment with coins. Put a penny at the bottom of the glass, and a nickel on top. It will lie horizontally, like a lid, although it does not reach the edge of the glass.
Now sharply blow on the edge of the penny.
He will stand on edge, and the penny will be thrown out by compressed air. After that, the penny will fall into place. So the invisible person helped you get a penny from the bottom of the glass, without touching either it or the penny lying on top.
Experience 3
A similar experiment can be done with egg glasses. Put two such glasses side by side and in the one closest to you, put an egg.
In case of failure, take a cool egg. And now blow strongly and sharply in the place indicated by the arrow in the figure, just at the very edge of the glass.
The egg will jump and “sit down” in an empty glass!
Invisible air slipped between the edge of the glass and the egg, burst into the glass, so much so that the egg jumped up!
For some, this experience does not work out - “there is not enough spirit”. But if you take an empty, blown-out shell instead of a hard-boiled egg, it will turn out for sure!
HEAVY AIR
Take a wide wooden ruler (which is not a pity). Balance it on the edge of the table so that with the slightest pressure on the free end, the ruler falls. And now spread a newspaper on the table over the ruler. Gently spread, smooth with your hands, straighten all the wrinkles.
Previously, the ruler could be tilted with a finger. Now a newspaper has been added, but how much does it weigh? Come on, bolder: get up from the ruler on the side and hit its end with your fist!
Even the fist hurt, and the ruler lies, as if nailed with nails. Well, now we'll show her how to resist! Take a stick and hit with all your might. Bach! The ruler is cut in half, and the newspaper lies to itself as if nothing had happened.
Why is the paper so heavy?
Yes, because air is pressing on it from above. 1 kg per square centimeter. And the newspaper has a lot of square centimeters! Well, guess what area it is? Approximately 60 x 42 = 2520 cm2. This means that the air presses on it with a force of two and a half thousand kilograms, two and a half tons!
Raise the newspaper slowly - air will penetrate under it and press from below with exactly the same force. But try to tear it off the table at once, and you have already seen what happens. The air does not have time to get under the newspaper - and the ruler breaks in half!
SUCKER FROM SCHOOL RUBBER
Of the three items named in the title, the octopus is the least convenient for experiments. Firstly, it is difficult to get it, and secondly, jokes are bad with the octopus. How it grabs with its terrible tentacles, how it sucks with suction cups - you won’t tear it off!
Zoologists say that the octopus sucker has the shape of a cup with a ring muscle. The octopus strains the muscle - the cup shrinks, it becomes narrower. And then, when this cup is pressed against the prey, the muscle relaxes.
Look how interesting: in order to hold prey, the octopus does not strain its muscles, but relaxes them! And still suckers stick. Like a radish on a plate!
Experience
From experiments with a live octopus, you and I had to refuse. But we will still make one sucker - an artificial sucker, from a school gum.
Take a soft rubber band and make a hole in the middle of one side. This will be the suction cup. Well, we use your muscles. After all, they are only needed to squeeze the suction cup at first, and then they still relax, so that the hand can be removed.
Squeeze the elastic to make the cup smaller and press it against the plate. Just moisten it first: the gum is not a radish, it does not have its own juice. By the way, the octopus also "works" with wet suction cups.
Pressed a rubber band?
Now let go, she sucked securely.
There are also soap dishes with rubber suction cups. They stick to the tiled bathroom wall. They, too, must first be moistened, and then pressed against the wall and released. Hold on!
Well, now about the fly!
Tell me, have you ever thought about how she walks on the wall and even on the ceiling?
There is even such a riddle: “What is above us upside down?” Maybe the fly has claws at the ends of its legs? Hooks with which she clings to the uneven walls and ceiling? But after all, she walks completely freely on the window glass, and on the mirror. There's really nothing for a fly to catch on to. It turns out that the fly also has suction cups on its paws.
So after that, assert that there is nothing in common between a fly and an octopus.
HOW TO EMPTY THE GLASS?
The glass and bottle are filled with water. You need to empty the glass with a bottle without emptying it.
Make two holes in the cork of the bottle and pierce two straws through them, one equal in length to the height of the glass, the other twice as long. Then seal one end of the smaller straw with bread crumb and plug the bottle with a cork so that the open ends of the straws fit into the bottle.
Now, if you turn the bottle upside down, water will begin to flow out of the large straw. Tip the bottle over a glass of water so that a small straw touches the bottom of the glass, and cut off with scissors its end sealed with bread crumb. Water will flow from the large straw until the glass is empty. Why?
This is explained as follows: straws act as a siphon. The void formed by the flowing water in the bottle is immediately filled with water from the glass, which is driven into the bottle by air pressure on the surface of the water in the glass.
If you think physics is a boring and unnecessary subject, then you are deeply mistaken. Our entertaining physics He will tell you why a bird sitting on a power line wire does not die from electric shock, and a person who has fallen into quicksand cannot drown in them. You will find out whether there really are no two identical snowflakes in nature and whether Einstein was a loser at school.
10 fun facts from the world of physics
Now we will answer the questions that concern many people.
Why does a train driver back up before moving off?
The reason for this is the static friction force, under the influence of which the train cars are standing still. If the locomotive simply moves forward, it may not move the train. Therefore, he slightly pushes them back, reducing the static friction force to zero, and then gives them acceleration, but in the other direction.
Are there identical snowflakes?
Most sources claim that in nature there are no identical snowflakes, since several factors influence their formation at once: humidity and air temperature, as well as the snow flight path. However, entertaining physics says: you can create two snowflakes of the same configuration.
This was experimentally confirmed by the researcher Karl Liebbrecht. Having created absolutely identical conditions in the laboratory, he obtained two superficially identical snow crystals. True, it should be noted: crystal cell they were still different.
Where is the largest reservoir of water in the solar system?
Never guess! The largest storage water resources our system is the Sun. The water is in the form of steam. Its highest concentration is noted in places that we call "spots on the Sun." Scientists even calculated that in these regions the temperature is one and a half thousand degrees lower than in the rest of our hot star.
What invention of Pythagoras was created to combat alcoholism?
According to legend, Pythagoras, in order to limit the use of wine, made a mug that could be filled with an intoxicating drink only up to a certain mark. It was worth exceeding the norm even by a drop, and the entire contents of the mug flowed out. This invention is based on the law of communicating vessels. The curved channel in the center of the mug does not allow it to be filled to the brim, “relieving” the container of all contents in the case when the liquid level is above the channel bend.
Is it possible to turn water from a conductor into an insulator?
Entertaining physics says: you can. Current conductors are not the water molecules themselves, but the salts contained in it, or rather their ions. If they are removed, the liquid will lose its ability to conduct electricity and become an insulator. In other words, distilled water is a dielectric.
How to survive in a falling elevator?
Many people think: you need to jump at the moment the cabin hits the ground. However, this opinion is incorrect, since it is impossible to predict when a landing will occur. Therefore, entertaining physics gives another advice: lie on your back on the floor of the elevator, trying to maximize the area of \u200b\u200bcontact with it. In this case, the impact force will not be directed to one part of the body, but will be evenly distributed over the entire surface - this will significantly increase your chances of survival.
Why does a bird sitting on a high voltage wire not die from electric shock?
The bodies of birds do not conduct electricity well. By touching the wire with its paws, the bird creates a parallel connection, but since it is not the best conductor, the charged particles do not move through it, but along the cable cores. But as soon as the bird comes into contact with a grounded object, it will die.
The mountains are closer to the source of heat than the plains, but on their peaks it is much colder. Why?
This phenomenon has a very simple explanation. The transparent atmosphere freely passes the sun's rays without absorbing their energy. But the soil perfectly absorbs heat. It is from it that the air then warms up. Moreover, the higher its density, the better it retains the thermal energy received from the earth. But high in the mountains, the atmosphere becomes rarefied, and therefore less heat “lingers” in it.
Can quicksand suck?
In films, there are often scenes where people "drown" in quicksand. IN real life- says entertaining physics - this is impossible. You won’t be able to get out of the sandy swamp on your own, because in order to pull out only one leg, you will have to make as much effort as it takes to lift a medium-weight car. But you also cannot drown, because you are dealing with a non-Newtonian fluid.
Rescuers advise in such cases not to make sudden movements, lie with your back down, spread your arms to the sides and wait for help.
Does nothing exist in nature, see the video:
Amazing cases from the life of famous physicists
Outstanding scientists, for the most part, are fanatics of their field, capable of anything for the sake of science. So, for example, Isaac Newton, trying to explain the mechanism of perception of light by the human eye, was not afraid to experiment on himself. He inserted a thin, carved ivory probe into the eye, simultaneously pressing on the back of the eyeball. As a result, the scientist saw rainbow circles in front of him and proved in this way: the world we see is nothing but the result of light pressure on the retina.
Russian physicist Vasily Petrov, who lived in early XIX century and engaged in the study of electricity, cut off the top layer of skin on his fingers to increase their sensitivity. At that time, there were no ammeters and voltmeters that could measure the strength and power of the current, and the scientist had to do it by touch.
The reporter asked A. Einstein if he writes down his great thoughts, and if he writes down, then where - in a notebook, notebook or a special card index. Einstein looked at the reporter's bulky notepad and said, "My dear! Real thoughts come so rarely to the head that it is not difficult to remember them.
But the Frenchman Jean-Antoine Nollet preferred to experiment on others. Conducting an experiment in the middle of the 18th century to calculate the transmission speed electric current, he connected 200 monks with metal wires and passed voltage through them. All participants in the experiment twitched almost simultaneously, and Nolle concluded: the current runs through the wires, well, oh, very quickly.
Almost every student knows the story that the great Einstein was a loser in his childhood. However, in fact, Albert studied very well, and his knowledge of mathematics was much deeper than the school curriculum required.
When the young talent tried to enter the Higher Polytechnic School, he scored highest mark in core subjects - mathematics and physics, but in other disciplines he had a slight shortage. On this basis, he was denied admission. The following year, Albert showed excellent results in all subjects, and at the age of 17 he became a student.
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What science is rich in interesting facts? Physics! Grade 7 is the time when schoolchildren begin to study it. So that a serious subject does not seem so boring, we suggest starting your studies with entertaining facts.
Why are there seven colors in the rainbow?
Interesting Facts about physics can even touch the rainbow! The number of colors in it was determined by Isaac Newton. Even Aristotle was interested in such a phenomenon as a rainbow, and its essence was discovered by Persian scientists in the 13-14th century. However, we are guided by the description of the rainbow that Newton made in his Optics in 1704. He singled out the colors with a glass prism.
If you look closely at the rainbow, you can see how the colors smoothly flow from one to another, forming a huge number of shades. And Newton initially singled out only five main ones: purple, blue, green, yellow, red. But the scientist had a passion for numerology, and therefore he wanted to bring the number of colors to the mystical number "seven". He added two more colors to the description of the rainbow - orange and blue. So it turned out a seven-color rainbow.
Liquid form
Physics is around us. Interesting facts may surprise us, even when it comes to such a familiar thing as ordinary water. We are all used to thinking that a liquid does not have its own shape, even a school textbook on physics says this! However, it is not. The natural shape of a liquid is a sphere.
Eiffel tower height
What is the exact height eiffel tower? And it depends on the weather! The fact is that the height of the tower fluctuates by as much as 12 centimeters. This is due to the fact that in hot sunny weather the building heats up, and the temperature of the beams can reach up to 40 degrees Celsius. And as you know, substances can expand under the influence of high temperature.
Selfless Scientists
Interesting facts about physicists can be not only funny, but also tell about their dedication and dedication to their favorite work. While studying an electric arc, physicist Vasily Petrov removed the top layer of skin on his fingertips to feel weak currents.
And Isaac Newton introduced a probe into his own eye to understand the nature of vision. The scientist believed that we see because light presses on the retina.
quicksand
Interesting facts about physics can help to understand the properties of such an entertaining thing as quicksand. They represent a Human or animal cannot completely sink into quicksand due to its high viscosity, but it is also very difficult to get out of it. To get your foot out of the quicksand, you need to make an effort comparable to lifting a car.
You can’t drown in it, but life is dangerous from dehydration, the sun, and hot flashes. If you get into quicksand, you need to lie on your back and wait for help.
supersonic speed
You know what was the first device that overcame the Common Shepherd's Whip. The click that frightens the cows is nothing more than a pop when overcoming. When hit hard, the tip of the whip moves so fast that it creates in the air shock wave. The same thing happens with an aircraft flying at supersonic speeds.
Photonic spheres
Interesting facts about the physics and nature of black holes are such that sometimes it is simply impossible to even imagine the implementation of theoretical calculations. As you know, light is made up of photons. Falling under the influence of the gravity of a black hole, photons form arcs, areas where they begin to orbit. Scientists believe that if you put a person in such a photon sphere, he will be able to see his own back.
Scotch
It is unlikely that you unwound tape in a vacuum, but scientists in their laboratories did it. And they found that when unwinding, a visible glow and X-rays appear. Power x-ray radiation such that it even allows you to take pictures of body parts! Why this happens is a mystery. A similar effect can be observed upon the destruction of asymmetric bonds in a crystal. But here's the problem - there is no crystalline structure in scotch tape. So scientists will have to come up with another explanation. Do not be afraid to unwind the tape at home - no radiation occurs in the air.
Experiments on humans
In 1746, the French physicist and part-time priest Jean-Antoine Nollet investigated the nature of the electric current. The scientist decided to find out what is the speed of the electric current. Here's just how to do it in a monastery...
The physicist invited 200 monks to the experiment, connected them with iron wires and discharged a battery from the recently invented Leyden jars into the poor fellows (they are the first capacitors). All the monks reacted to the blow at the same time, and this made it clear that the speed of the current was extremely high.
Genius Loser
Interesting facts from the life of physicists can give false hopes to underachieving students. There is a legend among negligent students that the famous Einstein was a real loser, did not know mathematics well and generally flunked his final exams. And nothing, became world We hasten to disappoint: Albert Einstein began to show remarkable mathematical abilities as a child and had knowledge that far exceeded the school curriculum.
Perhaps the rumors about the poor performance of the scientist arose because he did not immediately enter the Zurich Polytechnic School. Albert brilliantly passed the exams in physics and mathematics, but in other disciplines he did not score the required number of points. Having improved his knowledge in the necessary subjects, the future scientist successfully passed the exams the following year. He was 17 years old.
Birds on a wire
Have you noticed that birds love to sit on wires? But why don't they die from electric shock? The thing is that the body is not a very good conductor. The bird's paws create a parallel connection through which a small current flows. Electricity prefers wire, which is the best conductor. But as soon as the bird touches another element, for example, a grounded support, electricity rushes through its body, leading to death.
Hatches against fireballs
Interesting facts about physics can be remembered even while watching Formula 1 city races. Sports cars move at such high speeds that a low pressure is created between the bottom of the car and the road surface, which is enough to lift the hatch cover into the air. This is exactly what happened at one of the city races. The manhole cover collided with the next car, a fire broke out and the race was stopped. Since then, manhole covers have been welded to the rim to avoid accidents.
natural nuclear reactor
One of the most serious branches of science - nuclear physics. There are interesting facts here as well. Did you know that 2 billion years ago, a real natural nuclear reactor? The reaction proceeded for 100,000 years until the uranium vein was depleted.
An interesting fact is that the reactor was self-regulating - water entered the vein, which played the role of a neuron moderator. When active chain reaction the water boiled away and the reaction weakened.
