Simple but interesting physics experiments. Interesting physics experiments for children

Introduction

Without a doubt, all our knowledge begins with experience.
(Kant Emmanuel. German philosopher 1724-1804)

Physics experiments in an entertaining way familiarize students with the various applications of the laws of physics. Experiments can be used in the classroom to draw the attention of students to the phenomenon being studied, while repeating and consolidating educational material, at physical evenings. Entertaining experiments deepen and expand the knowledge of students, contribute to the development of logical thinking, instill an interest in the subject.

This work describes 10 entertaining experiments, 5 demonstration experiments using school equipment. The authors of the works are students of the 10th grade of the secondary school No. 1 of the village of Zabaikalsk, Zabaikalsky Krai - Chuguevsky Artyom, Lavrentyev Arkady, Chipizubov Dmitry. The guys independently performed these experiments, summarized the results and presented them in the form of this work

The role of experiment in science physics

That physics is a young science
To say for sure, it is impossible here
And in ancient times, knowing science,
We always tried to comprehend it.

The goal of teaching physics is specific,
To be able to apply all knowledge in practice.
And it's important to remember - the role of experiment
Should stand in the first place.

Be able to plan and execute an experiment.
Analyze and bring to life.
Build a model, put forward a hypothesis,
Strive to reach new heights

The laws of physics are based on empirically established facts. Moreover, the interpretation of the same facts often changes in the course of the historical development of physics. Facts accumulate through observation. But at the same time, one cannot be limited only to them. This is only the first step towards knowledge. Next comes the experiment, the development of concepts that allow for qualitative characteristics. In order to draw general conclusions from observations, to find out the causes of the phenomena, it is necessary to establish quantitative relationships between the quantities. If such a dependence is obtained, then a physical law is found. If a physical law is found, then there is no need to put an experiment in each individual case, it is enough to perform the appropriate calculations. Having studied experimentally the quantitative relationships between quantities, it is possible to identify patterns. On the basis of these regularities, a general theory of phenomena is being developed.

Consequently, there can be no rational teaching of physics without experiment. The study of physics presupposes the widespread use of experiment, discussion of the features of its formulation and the observed results.

Entertaining experiments in physics

The description of the experiments was carried out using the following algorithm:

1. Experience name
2. Devices and materials required for experience
3. Stages of the experiment
4. Explaining the experience

Experience No. 1 Four floors

Appliances and materials: glass, paper, scissors, water, salt, red wine, sunflower oil, colored alcohol.

Stages of the experiment

Let's try to pour four different liquids into a glass so that they don't mix and stand five stories above the other. However, it will be more convenient for us to take not a glass, but a narrow glass that expands to the top.

1. Pour salted tinted water onto the bottom of the glass.
2. Roll "Funtik" out of paper and bend its end at a right angle; cut off the tip. The hole in the Funtik should be about the size of a pinhead. Pour red wine into this horn; a thin stream should flow out of it horizontally, break against the walls of the glass and drain onto the salt water.
   When the height of the layer of red wine is equal to the height of the layer of colored water, stop pouring the wine.
3. From the second horn, pour the sunflower oil into a glass in the same way.
4. Pour a layer of colored alcohol from the third horn.

Picture 1

So we got four floors of liquids in one glass. All are of different colors and different densities.

Explaining the experience

The liquids in the grocery are arranged in the following order: tinted water, red wine, sunflower oil, tinted alcohol. The heaviest are at the bottom, the lightest are at the top. Salt water has the highest density, tinted alcohol has the smallest density.

Experience # 2 Amazing candlestick

Appliances and materials: candle, nail, glass, matches, water.

Stages of the experiment

Isn't it an amazing candlestick - a glass of water? And this candlestick is not bad at all.

Picture 2

1. Weight the end of the candle with a nail.
2. Calculate the size of the nail so that the candle is completely immersed in water, only the wick and the very tip of the paraffin should protrude above the water.
3. Light the fuse.

Explaining the experience

Let them tell you, because in a minute the candle will burn out to the water and go out!

The fact of the matter, you will answer, is that the candle is shorter by the minute. And if it is shorter, then it is easier. If it's easier, then it will float up.

And, it is true, the candle will float up a little, and the water-cooled paraffin at the edge of the candle will melt more slowly than the paraffin surrounding the wick. Therefore, a rather deep funnel forms around the wick. This emptiness, in turn, makes the candle lighter, which is why our candle will burn out to the end.

Experience number 3 Candle by bottle

Appliances and materials: candle, bottle, matches

Stages of the experiment

1. Place a lighted candle behind the bottle, and stand yourself so that your face is 20-30 cm from the bottle.
2. It is worth blowing now, and the candle will go out, as if there is no barrier between you and the candle.

Figure 3

Explaining the experience

The candle goes out because the bottle is “flowed around” by the air: the air stream is broken by the bottle into two streams; one flows around it on the right, and the other on the left; and they are found approximately where there is a candle flame.

Experience number 4 Swirling snake

Appliances and materials: thick paper, candle, scissors.

Stages of the experiment

1. Cut a spiral out of thick paper, stretch it slightly and place it on the end of the curved wire.
2. By keeping this spiral above the candle in an upward flow of air, the snake will rotate.

Explaining the experience

The snake rotates because there is an expansion of air under the influence of heat and the transformation of warm energy into movement.

Figure 4

Experience number 5 The eruption of Vesuvius

Devices and materials: glass vessel, vial, cork, alcohol ink, water.

Stages of the experiment

1. Put a bottle of alcohol mascara in a wide glass vessel filled with water.
2. There should be a small hole in the bubble stopper.

Figure 5

Explaining the experience

Water has a higher density than alcohol; it will gradually enter the bubble, displacing the mascara from there. A red, blue or black liquid will rise upward from the bubble in a thin stream.

Experiment number 6 Fifteen matches on one

Apparatus and materials: 15 matches.

Stages of the experiment

1. Put one match on the table, and 14 matches across it so that their heads stick out upward, and the ends touch the table.
2. How to pick up the first match, holding it by one end, and with it all the other matches?

Explaining the experience

To do this, you only need to put one more, fifteenth match on top of all the matches, in the hollow between them

Figure 6

Experiment No. 7 Pot holder

Appliances and materials: plate, 3 forks, napkin ring, saucepan.

Stages of the experiment

1. Place three forks in the ring.
2. Put a plate on this structure.
3. Place a pot of water on a stand.

Figure 7

Figure 8

Explaining the experience

This experience is explained by the rule of leverage and stable equilibrium.

Figure 9

Experience number 8 Paraffin motor

Appliances and materials: candle, knitting needle, 2 glasses, 2 plates, matches.

Stages of the experiment

We don't need electricity or gas to make this motor. For this we only need ... a candle.

1. Heat the knitting needle and stick it with their heads into the candle. This will be the axis of our engine.
2. Place the candle on the edges of two glasses with a knitting needle and balance.
3. Light a candle at both ends.

Explaining the experience

A drop of paraffin will fall into one of the plates placed under the ends of the candle. The balance will be violated, the other end of the candle will drag and drop; at the same time, a few drops of paraffin will drain from it, and it will become lighter than the first end; it rises to the top, the first end will go down, drop a drop, become lighter, and our motor will start to work with might and main; gradually the fluctuations of the candle will increase more and more.

Figure 10

Experience No. 9 Free exchange of fluids

Appliances and materials: orange, glass, red wine or milk, water, 2 toothpicks.

Stages of the experiment

1. Carefully cut the orange in half, peel so that the skin peels off with a whole cup.
2. Poke two holes next to it in the bottom of this cup and put it in the glass. The diameter of the cup should be slightly larger than the diameter of the central part of the glass, then the cup will hold onto the walls without falling to the bottom.
3. Dip the orange cup into the vessel one third of its height.
4. Pour red wine or tinted alcohol into an orange peel. It will go through the hole until the wine level reaches the bottom of the cup.
5. Then pour water almost to the brim. You can see how the stream of wine rises through one of the holes to the water level, while the heavier water will pass through the other hole and begin to sink to the bottom of the glass. In a few moments, the wine will be at the top, and the water is at the bottom.

Experience number 10 Singing glass

Apparatus and materials: thin glass, water.

Stages of the experiment

1. Fill the glass with water and wipe the edges of the glass.
2. Rub the glasses with a moistened finger anywhere, she will sing.

Figure 11

Demonstration experiments

1. Diffusion of liquids and gases

Diffusion (from Lat. Diflusio - spreading, spreading, scattering), the transfer of particles of different nature, due to the chaotic thermal movement of molecules (atoms). Distinguish between diffusion in liquids, gases and solids

Demonstration experiment "Observation of diffusion"

Devices and materials: cotton wool, ammonia, phenolphthalein, installation for observing diffusion.

Experiment steps

1. Take two pieces of cotton wool.
2. Soak one piece of cotton wool with phenolphthalein, the other with ammonia.
3. Let's bring the branches into contact.
4. There is a pink staining of the fleece due to the phenomenon of diffusion.

Figure 12

Figure 13

Figure 14

The phenomenon of diffusion can be observed using a special installation

1. Pour ammonia into one of the cones.
2. Soak a piece of cotton wool with phenolphthalein and put it on top of the cone.
3. After a while, we observe the coloring of the fleece. This experiment demonstrates the phenomenon of diffusion at a distance.

Figure 15

Let us prove that the phenomenon of diffusion depends on temperature. The higher the temperature, the faster the diffusion proceeds.

Figure 16

To demonstrate this experience, let's take two identical glasses. Pour cold water into one glass, hot water into the other. Add copper sulfate to the glasses, we observe that copper sulfate dissolves faster in hot water, which proves the dependence of diffusion on temperature.

Figure 17

Figure 18

2. Communicating vessels

To demonstrate communicating vessels, let us take a number of vessels of various shapes, connected at the bottom by tubes.

Figure 19

Figure 20

We will pour liquid into one of them: we will immediately find that the liquid will flow through the tubes into the other vessels and will settle in all vessels at the same level.

The explanation for this experience is as follows. The pressure on the free surfaces of the liquid in the vessels is the same; it is equal to atmospheric pressure. Thus, all free surfaces belong to the same level surface and, therefore, must be in the same horizontal plane, and the upper edge of the vessel itself must be in the same horizontal plane: otherwise, the kettle cannot be poured to the top.

Figure 21

3 Pascal's ball

Pascal ball is a device designed to demonstrate the uniform transmission of pressure produced on a liquid or gas in a closed vessel, as well as the rise of liquid behind the piston under the influence of atmospheric pressure.

To demonstrate the uniform transmission of the pressure produced on the liquid in a closed vessel, it is necessary, using a piston, to draw water into the vessel and tightly put a ball on the branch pipe. By pushing the piston into the vessel, demonstrate the outflow of liquid from the holes in the ball, paying attention to the uniform outflow of liquid in all directions.

Ministry of Education and Science of the Chelyabinsk Region

Plastovskiy technological branch

GBPOU SPO "Kopeysk Polytechnic College named after S.V Khokhryakova "

MASTER CLASS

"EXPERIENCES AND EXPERIMENTS

FOR KIDS"

Educational - research work

"Entertaining physical experiences

from scrap materials "

Leader: Yu.V. Timofeeva, physics teacher

Performers: students of the OPI group - 15

annotation

Physical experiments increase interest in the study of physics, develop thinking, teach to apply theoretical knowledge to explain various physical phenomena occurring in the surrounding world.

Unfortunately, due to the overload of the educational material in physics lessons, insufficient attention is paid to entertaining experiments.

With the help of experiments, observations and measurements, dependences between various physical quantities can be investigated.

All the phenomena observed during entertaining experiments have a scientific explanation, for this they used the fundamental laws of physics and the properties of the matter around us.

TABLE OF CONTENTS

	Introduction
	Main content
	Organization of research work
	Methodology for conducting various experiments
	Research results
	Conclusion
	List of used literature
	Applications

INTRODUCTION

Without a doubt, all our knowledge begins with experience.

(Kant Emmanuel - German philosopher 1724-1804)

Physics is not only scientific books and complex laws, not only huge laboratories. Physics is also interesting experiments and entertaining experiments. Physics are magic tricks shown in a circle of friends, funny stories and funny homemade toys.

Most importantly, any material at hand can be used for physical experiments.

Physical experiments can be done with balloons, glasses, syringes, pencils, straws, coins, needles, etc.

Experiments increase interest in the study of physics, develop thinking, teach to apply theoretical knowledge to explain various physical phenomena occurring in the surrounding world.

When conducting experiments, it is necessary not only to draw up a plan for its implementation, but also to determine the methods for obtaining some data, to independently assemble installations and even to design the necessary devices for reproducing this or that phenomenon.

But, unfortunately, due to the overload of the educational material in physics lessons, insufficient attention is paid to entertaining experiments, much attention is paid to theory and problem solving.

Therefore, it was decided to conduct research work on the topic "Entertaining experiments in physics from scrap materials."

The objectives of the research work are as follows:

1. To master the methods of physical research, to master the skills of correct observation and the technique of physical experiment.

   Organization of independent work with various literature and other sources of information, collection, analysis and generalization of material on the topic of research work.

   Teach students, apply scientific knowledge to explain physical phenomena.

   To instill in students love for physics, to strengthen their concentration on understanding the laws of nature, and not on their mechanical memorization.

When choosing a research topic, we proceeded from the following principles:

Subjectivity - the chosen topic is in our interests.

Objectivity - the topic we have chosen is relevant and important in scientific and practical terms.

Ability - the tasks and goals we set in our work are real and achievable.

1. MAIN CONTENT.

The research work was carried out according to the following scheme:

Formulation of the problem.

Study of information from various sources on this issue.

The choice of research methods and their practical mastery.

Collecting your own material - collecting materials at hand, conducting experiments.

Analysis and generalization.

Formulation of conclusions.

During the research work, the following physical research methods were used:

1. Physical experience

The experiment consisted of the following stages:

Clarification of the conditions of the experiment.

This stage provides for an acquaintance with the conditions of the experiment, determination of the list of necessary improvised devices and materials and safe conditions during the experiment.

Drawing up a sequence of actions.

At this stage, the procedure for conducting the experiment was outlined, if necessary, new materials were added.

Experiment.

2. Observation

When observing the phenomena occurring in the experiment, we paid special attention to the change in physical characteristics, while we were able to detect regular connections between various physical quantities.

3. Simulation.

Simulation is the foundation of any physical research. During the experiments, we simulated various situational experiments.

In total, we have modeled, conducted and scientifically explained several entertaining physical experiments.

2. Organization of research work:

2.1 Technique for conducting various experiments:

Experience No. 1 Candle by bottle

Devices and materials: candle, bottle, matches

Stages of the experiment

Place a lighted candle behind the bottle, and stand yourself so that your face is 20-30 cm from the bottle.

It is worth blowing now, and the candle will go out, as if there is no barrier between you and the candle.

Experience number 2 Swirling snake

Appliances and materials: thick paper, candle, scissors.

Stages of the experiment

Cut a spiral out of thick paper, stretch it slightly and place it on the end of the curved wire.

By keeping this spiral above the candle in an upward flow of air, the snake will rotate.

Devices and materials: 15 matches.

Stages of the experiment

Put one match on the table, and 14 matches across it so that their heads stick out upward, and the ends touch the table.

How to pick up the first match, holding it by one end, and with it all the other matches?

Experience number 4 Paraffin motor

Devices and materials:candle, knitting needle, 2 glasses, 2 plates, matches.

Stages of the experiment

We don't need electricity or gas to make this motor. For this we only need ... a candle.

Heat the knitting needle and stick it with their heads into the candle. This will be the axis of our engine.

Place the candle on the edges of two glasses with a knitting needle and balance.

Light a candle at both ends.

Experiment # 5 Thick air

We live by the air we breathe. If this doesn't seem magical enough to you, do this experiment to find out what other magic the air is capable of.

Props

Protective glasses

Pine plank 0.3x2.5x60 cm (can be purchased at any lumber store)

Newspaper sheet

Ruler

Preparation

Let's start the scientific magic!

Wear safety glasses. Announce to the audience: “There are two kinds of air in the world. One is skinny and the other is fat. Now I will do magic with the help of greasy air. "

Place the plank on the table so that about 6 inches (15 cm) protrudes over the edge of the table.

Say: "Thick air, sit on the board." Hit the end of the board that protrudes over the edge of the table. The board will jump into the air.

Tell the audience that a thin air must have sat on the board. Put the plank back on the table as in step 2.

Place a piece of newsprint on the board as shown in the illustration, with the board in the middle of the sheet. Smooth the newspaper so that there is no air between it and the table.

Say again, "Thick air, sit on the plank."

Hit the protruding end with the edge of your palm.

Experience No. 6 Waterproof paper

Props

Paper towel

Cup

A plastic bowl or bucket that can hold enough water to completely cover the glass

Preparation

Lay out everything you need on the table

Let's start the scientific magic!

Announce to the audience: "With the help of my magical skill, I can make the piece of paper dry."

Crumple up a paper towel and place it on the bottom of your glass.

Turn the glass over and make sure the wad of paper stays in place.

Say some magic words over the glass, for example: "magical powers, protect the paper from water." Then slowly lower the inverted glass into a bowl of water. Try to keep the glass as level as possible until it is completely hidden under water.

Take the glass out of the water and shake off the water. Turn the glass upside down and take out the paper. Let the audience feel it and make sure it stays dry.

Experience number 7 Flying ball

Have you seen a man rise into the air at a magician's performance? Try a similar experiment.

Please note: This experiment will require a hairdryer and adult help.

Props

Hairdryer (must be used only by an adult helper)

2 thick books or other heavy objects

Ping pong ball

Ruler

Adult assistant

Preparation

Place the hairdryer on the table with the hot air blowing hole upwards.

Use books to set it in this position. Make sure they don't block the opening on the side where the air is drawn into the hair dryer.

Plug in the hair dryer.

Let's start the scientific magic!

Ask an adult audience member to be your assistant.

Announce to the audience: "Now I will make an ordinary ping-pong ball fly through the air."

Take the ball in your hand and let it go so that it falls on the table. Tell the audience: “Oops! I forgot to say the magic words! "

Say the magic words over the ball. Have your assistant turn on the hair dryer at full power.

Place the balloon gently over a hairdryer in a stream of air, about 45 cm from the blow hole.

Tips for the learned wizard

Depending on the force of blowing, you may need to place the balloon slightly higher or lower than indicated.

What else can you do

Try to do the same with balls of different sizes and weights. Will the experience be equally good?

2.2 RESULTS OF THE STUDY:

1) Experience No. 1 Candle by bottle

Explanation:

The candle will float little by little, and the water-cooled paraffin at the edge of the candle will melt more slowly than the paraffin surrounding the wick. Therefore, a rather deep funnel forms around the wick. This emptiness, in turn, lightens the candle, which is why our candle will burn out to the end..

2) Experience number 2 Swirling snake

Explanation:

The snake rotates because there is an expansion of air under the influence of heat and the transformation of warm energy into movement.

3) Experience number 3 Fifteen matches on one

Explanation:

In order to raise all the matches, you only need to put one more, fifteenth match on top of all the matches, in the hollow between them.

4) Experiment No. 4 Paraffin motor

Explanation:

A drop of paraffin will fall into one of the plates placed under the ends of the candle. The balance will be violated, the other end of the candle will drag and drop; at the same time, a few drops of paraffin will drain from it, and it will become lighter than the first end; it rises to the top, the first end will go down, drop a drop, become lighter, and our motor will start to work with might and main; gradually the fluctuations of the candle will increase more and more.

5) Experience number 5 Thick air

When you hit the board for the first time, it bounces. But if you hit the board with the newspaper on it, the board breaks.

Explanation:

When you smooth out a newspaper, you remove almost all the air from under it. At the same time, a large amount of air on top of the newspaper presses on it with great force. When you hit the board, it breaks because the air pressure on the newspaper prevents the board from rising up in response to the force you put on.

6) Experience number 6 Waterproof paper

Explanation:

Air takes up a certain volume. There is air in the glass, no matter in which position it is. When you turn the glass upside down and slowly lower it into the water, the air remains in the glass. Water cannot enter the glass due to air. The air pressure turns out to be greater than the pressure of water tending to penetrate into the glass. The towel on the bottom of the glass remains dry. If the glass is turned on its side under water, air in the form of bubbles will come out of it. Then he can get into the glass.

8) Experience number 7 Flying ball

Explanation:

In fact, this trick does not contradict the force of gravity. It demonstrates an important ability of air called the Bernoulli principle. Bernoulli's principle is a law of nature, according to which any pressure of any fluid substance, including air, decreases with increasing speed of its movement. In other words, at a low air flow rate, it has a high pressure.

The air coming out of the hair dryer moves very quickly and therefore its pressure is low. The ball is surrounded on all sides by an area of ​​low pressure, which forms a cone at the hole of the hair dryer. The air around this cone has a higher pressure, and does not allow the ball to fall out of the low pressure zone. The force of gravity pulls it down, and the force of the air pulls it up. Thanks to the combined action of these forces, the ball hangs in the air above the hair dryer.

CONCLUSION

Analyzing the results of entertaining experiments, we were convinced that the knowledge gained in physics lessons is quite applicable to solving practical issues.

With the help of experiments, observations and measurements, the relationships between various physical quantities were investigated.

All the phenomena observed during entertaining experiments have a scientific explanation, for this we used the fundamental laws of physics and the properties of the matter around us.

The laws of physics are based on empirically established facts. Moreover, the interpretation of the same facts often changes in the course of the historical development of physics. Facts accumulate through observation. But at the same time, one cannot be limited only to them. This is only the first step towards knowledge. Next comes the experiment, the development of concepts that allow for qualitative characteristics. In order to draw general conclusions from observations, to find out the causes of the phenomena, it is necessary to establish quantitative relationships between the quantities. If such a dependence is obtained, then a physical law is found. If a physical law is found, then there is no need to put an experiment in each individual case, it is enough to perform the appropriate calculations. Having studied experimentally the quantitative relationships between quantities, it is possible to identify patterns. On the basis of these regularities, a general theory of phenomena is being developed.

Consequently, there can be no rational teaching of physics without experiment. The study of physics and other technical disciplines presupposes extensive use of the experiment, discussion of the features of its formulation and the observed results.

In accordance with the task at hand, all experiments were carried out using only cheap, small-sized materials at hand.

Based on the results of educational research work, the following conclusions can be drawn:

1. In various sources of information, one can find and come up with many entertaining physical experiments performed with the help of improvised equipment.

   Entertaining experiments and home-made physical devices increase the range of demonstrations of physical phenomena.

   Entertaining experiments allow you to test the laws of physics and theoretical hypotheses.

BIBLIOGRAPHY

M. Di Spezio "Entertaining Experiments", LLC "Astrel", 2004.

F.V. Rabiza "Funny Physics", Moscow, 2000.

L. Halperstein "Hello, Physics", Moscow, 1967.

A. Tomilin "I want to know everything", Moscow, 1981.

M.I. Bludov "Conversations on Physics", Moscow, 1974.

ME AND. Perelman "Entertaining tasks and experiments", Moscow, 1972.

ANNEXES

Disk:

1. Presentation "Entertaining physical experiments from scrap materials"

2. Video "Entertaining physical experiments from scrap materials"

Good afternoon, guests of the Eureka Research Institute website! Do you agree that knowledge supported by practice is much more effective than theory? Entertaining experiments in physics will not only perfectly entertain, but will also arouse the child's interest in science, and will also remain in the memory much longer than a paragraph in a textbook.

What will experiences teach children?

We bring to your attention 7 experiments with an explanation, which will surely raise the question of the kid "Why?" As a result, the child learns that:

• By mixing 3 primary colors: red, yellow and blue, you can get additional ones: green, orange and purple. Have you thought about paints? We offer you another, unusual way to make sure of this.
• Light reflects off a white surface and turns into heat when it hits a black object. What can this lead to? Let's figure it out.
• All objects are subject to gravity, that is, they tend to a state of rest. In practice, this looks fantastic.
• Objects have a center of mass. So what? Let's learn how to benefit from this.
• A magnet is an invisible, but powerful force of some metals, capable of endowing you with the powers of a magician.
• Static electricity can not only attract your hair, but it can also sort out small particles.

So let's make our kids proficient!

1. Create a new color

This experiment will be useful for preschoolers and younger students. For the experiment, we will need:

• Lantern;
• red, blue and yellow cellophane;
• ribbon;
• white wall.

We carry out the experiment near the white wall:

• We take the lantern, cover it first with red and then yellow cellophane, after which we turn on the light. We look at the wall and see an orange reflection.
• Now we remove the yellow cellophane and put on the blue bag over the red one. Our wall is lit in purple.
• And if the lantern is covered with blue and then yellow cellophane, then we will see a green spot on the wall.
• This experiment can be continued with other colors.

2. Black color and sunbeam: explosive combination

To carry out the experiment you will need:

• 1 transparent and 1 black balloon;
• magnifier;
• Sun Ray.

This experience will take some knack, but you can do it.

• First you need to inflate the transparent balloon. Hold it tight, but don't tie the tip.
• Now, using the blunt end of a pencil, push the black balloon inside the transparent one halfway.
• Inflate the black balloon inside the transparent one until it is about half its volume.
• Tie the tip of a black ball and push it into the middle of the transparent ball.
• Inflate the transparent balloon a little more and tie the end.
• Position the magnifying glass so that the sunbeam hits the black ball.
• In a few minutes, the black ball will burst inside the transparent one.

Tell your toddler that transparent materials let in sunlight, so we can see the street through the window. A black surface, on the other hand, absorbs light rays and turns them into heat. That is why it is recommended to wear light-colored clothing in the heat to avoid overheating. When the black ball heated up, it began to lose its elasticity and burst under the pressure of internal air.

3. Lazy ball

The next experience is a real show, but it will take some practice to run it. The school explains this phenomenon in the 7th grade, but in practice it can be done even at preschool age. Prepare the following items:

• plastic cup;
• metal dish;
• toilet paper cardboard sleeve;
• tennis ball;
• meter;
• broom.

How do you carry out this experiment?

• So, place the glass on the edge of the table.
• Place the dish on the glass so that its edge on one side is above the floor.
• Place the base of the toilet paper roll in the center of the dish, directly above the glass.
• Place the ball on top.
• Stand half a meter from the structure with a broom in your hand so that its rods are bent towards your feet. Stand on top of them.
• Now pull back the broom and release it sharply.
• The handle will hit the dish, and it, together with the cardboard sleeve, will fly away to the side, and the ball will fall into the glass.

Why didn't he fly away with the rest of the items?

Because, according to the law of inertia, an object that is not acted upon by other forces tends to remain at rest. In our case, only the force of gravity to the Earth acted on the ball, so it fell down.

4. Raw or boiled?

Let's introduce the child to the center of mass. To do this, take:

A cooled, hard-boiled egg;

2 raw eggs

Invite a group of children to distinguish a boiled egg from a raw one. At the same time, you cannot break eggs. Say that you can do it without error.

1. Unroll both eggs on the table.
2. An egg that is spinning faster and at a steady speed is boiled.
3. To prove your point, break another egg into a bowl.
4. Take a second raw egg and a paper towel.
5. Ask a spectator to make the egg sit on the blunt end. Nobody can do that, except you, since only you know the secret.
6. Just shake the egg vigorously up and down for half a minute, then set it on a napkin without any problems.

Why do eggs behave differently?

They, like any other object, have a center of mass. That is, different parts of an object may not weigh the same, but there is a point that divides its mass into equal parts. In a boiled egg, due to a more uniform density, the center of mass remains in the same place during rotation, while in a raw egg it shifts along with the yolk, which makes it difficult to move. In a raw egg that has been shaken, the yolk sinks to the blunt end and the center of mass is there, so it can be placed.

5. "Golden" mean

Invite the children to find the middle of the stick without a ruler, but just by eye. Evaluate the result with a ruler and say that it is not entirely correct. Now do it yourself. A mop handle works best.

• Raise the stick to waist level.
• Place it on 2 index fingers, holding them at a distance of 60 cm.
• Move your fingers closer together and make sure that the stick does not lose balance.
• When your fingers come together and the stick is parallel to the floor, you have reached your goal.
• Place the stick on the table, keeping your finger on the desired mark. Make sure with a ruler that you did the job accurately.

Tell your child that you have found not just the middle of the stick, but its center of mass. If the object is symmetrical, then it will coincide with its middle.

6. Zero gravity in the bank

Let's make the needles hang in the air. To do this, take:

• 2 strands of 30 cm;
• 2 needles;
• transparent tape;
• liter jar and lid;
• ruler;
• small magnet.

How to carry out the experiment?

• Thread the needles and tie the ends with two knots.
• Tape the knots to the bottom of the jar so that there is about 1 inch (2.5 cm) to the edge of the jar.
• From the inside of the lid, glue the tape in a loop, sticky side out.
• Place the lid on a table and glue the magnet to the hinge. Turn the jar over and screw the lid back on. The needles will hang down and pull towards the magnet.
• When you turn the jar upside down, the needles will still reach for the magnet. You may need to lengthen the threads if the magnet does not hold the needles upright.
• Now unscrew the lid and place it on the table. You are ready to conduct the experience in front of the audience. As soon as you screw the lid back on, the needles from the bottom of the can will shoot upward.

Tell your child that the magnet attracts iron, cobalt and nickel, so iron needles are susceptible to it.

7. "+" and "-": useful attraction

Your child has probably noticed how hair is magnetically attached to certain fabrics or combs. And you told him that static electricity is to blame. Let's do an experiment from the same series and show what else the "friendship" of negative and positive charges can lead to. We will need:

• paper towel;
• 1 tsp salt and 1 tsp. pepper;
• spoon;
• balloon;
• woolen thing.

Experiment stages:

• Place a paper towel on the floor and sprinkle the salt and pepper mixture on it.
• Ask your child: how now to separate salt from pepper?
• Rub the inflated ball on the woolen thing.
• Bring it to salt and pepper.
• The salt will stay in place and the pepper will be magnetised to the ball.

After rubbing against wool, the ball acquires a negative charge, which attracts the positive ions of the pepper. The electrons of the salt are not so mobile, so they do not react to the approach of the ball.

Experiences at home are valuable life experiences

Admit it, you yourself were interested in watching what was happening, and even more so for the child. By doing amazing tricks with the simplest substances, you will teach your baby:

• trust you;
• see the amazing in everyday life;
• fascinating to learn the laws of the world around;
• develop versatile;
• learn with interest and desire.

We remind you once again that developing a child is easy and you don't need to have a lot of money and time for this. See you soon!

Tens and hundreds of thousands of physical experiments have been performed over the thousand-year history of science. It is not easy to select a few "very best" to tell about them. What should be the selection criteria?

Four years ago, The New York Times published an article by Robert Crees and Stony Beech. It described the results of a survey conducted among physicists. Each interviewee had to name the ten most beautiful in the history of physics experiments. In our opinion, the criterion of beauty is in no way inferior to other criteria. Therefore, we will tell you about the experiments included in the top ten according to the results of the survey of Kriez and Buk.

1. Experiment of Eratosthenes of Cyrene

One of the oldest known physical experiments, as a result of which the radius of the Earth was measured, was carried out in the 3rd century BC by the librarian of the famous Library of Alexandria, Erastophenes of Cyrene.

The experimental design is simple. At noon, on the day of the summer solstice, in the city of Siena (now Aswan), the Sun was at its zenith and objects did not cast a shadow. On the same day and at the same time in the city of Alexandria, located 800 kilometers from Siena, the Sun deviated from the zenith by about 7 °. This is about 1/50 of a full circle (360 °), from which it turns out that the circumference of the Earth is 40,000 kilometers, and the radius is 6,300 kilometers.

It seems almost unbelievable that the Earth's radius measured by such a simple method turned out to be only 5% less than the value obtained by the most accurate modern methods.

2. Galileo Galilei's experiment

In the 17th century, the dominant point of view of Aristotle, who taught that the speed of the fall of a body depends on its mass. The heavier the body, the faster it falls. The observations that each of us can do in everyday life would seem to confirm this.

Try to release a light toothpick and a heavy stone at the same time. The stone will touch the ground faster. Such observations led Aristotle to the conclusion about the fundamental property of the force with which the Earth attracts other bodies. In fact, the fall speed is influenced not only by the force of gravity, but also by the force of air resistance. The ratio of these forces for light objects and for heavy objects is different, which leads to the observed effect. The Italian Galileo Galilei questioned the correctness of Aristotle's conclusions and found a way to test them. To do this, he dropped a cannonball and a much lighter musket bullet from the Leaning Tower of Pisa at the same moment. Both bodies had approximately the same streamlined shape, therefore, both for the core and for the bullet, the air resistance forces were negligible compared to the forces of attraction.

Galileo found out that both objects reach the ground at the same moment, that is, the speed of their fall is the same. The results obtained by Galileo. - a consequence of the law of universal gravitation and the law according to which the acceleration experienced by the body is directly proportional to the force acting on it, and inversely proportional to the mass.

3. Another experiment of Galileo Galilei

Galileo measured the distance that the balls, rolling on an inclined board, covered in equal intervals of time, measured by the author of the experiment on a water clock. The scientist found that if the time is doubled, the balls will roll four times further. This quadratic relationship meant that the balls under the action of gravity move at an accelerated rate, which contradicted the assertion of Aristotle, taken on faith for 2000 years, that bodies on which a force acts move at a constant speed, whereas if the force is not applied to the body, then it is at rest.

The results of this experiment of Galileo, like the results of his experiment with the Leaning Tower of Pisa, later served as the basis for the formulation of the laws of classical mechanics.

4. Henry Cavendish's experiment

After Isaac Newton formulated the law of universal gravitation: the force of attraction between two bodies with masses of Meath, located at a distance r from each other, is equal to F = G (mM / r2), it remained to determine the value of the gravitational constant G. To do this, it was necessary to measure the force attraction between two bodies with known masses. This is not so easy to do, because the gravity is very small.

We feel the gravitational pull of the Earth. But it is impossible to feel the attraction of even a very large nearby mountain, because it is very weak. A very subtle and sensitive method was needed. It was invented and applied in 1798 by Newton's compatriot Henry Cavendish. He used a torsion balance - a rocker with two balls suspended from a very thin string. Cavendish measured the displacement of the rocker arm (rotation) when approaching the balls of the balance of other balls of greater mass.

To increase the sensitivity, the displacement was determined by the light beams reflected from the mirrors mounted on the balls of the rocker arm. As a result of this experiment, Cavendish managed to quite accurately determine the value of the gravitational constant and for the first time calculate the mass of the Earth.

5. The experiment of Jean Bernard Foucault

French physicist Jean Bernard Leon Foucault in 1851 experimentally proved the rotation of the Earth around its axis using a 67-meter pendulum suspended from the top of the dome of the Parisian Pantheon. The swing plane of the pendulum remains unchanged in relation to the stars. The observer, who is on the Earth and rotates with it, sees that the plane of rotation is slowly turning in the direction opposite to the direction of the Earth's rotation.

6. Isaac Newton's experiment

In 1672, Isaac Newton performed a simple experiment that is described in all school textbooks. Having closed the shutters, he made a small hole in them through which the sunbeam passed. A prism was placed in the path of the beam, and a screen was placed behind the prism.

On the screen, Newton observed a "rainbow": a white sunbeam, passing through a prism, turned into several colored rays - from violet to red. This phenomenon is called light dispersion. Sir Isaac was not the first to observe this phenomenon. Already at the beginning of our era, it was known that large monocrystals of natural origin have the property of decomposing light into colors. The first studies of light dispersion in experiments with a triangular glass prism even before Newton were carried out by the Englishman Chariot and the Czech naturalist Marci.

However, before Newton, such observations were not subjected to serious analysis, and the conclusions drawn on their basis were not verified by additional experiments. Both Chariot and Marzi remained followers of Aristotle, who argued that the difference in color is determined by the difference in the amount of darkness "mixed" with white light. Violet, according to Aristotle, occurs with the greatest addition of darkness to light, and red - with the least. Newton, on the other hand, did additional experiments with crossed prisms, when light transmitted through one prism then passes through another. Based on the totality of his experiments, he concluded that "no color arises from whiteness and blackness mixed together, except for intermediate dark ones; the amount of light does not change the type of color." He showed that white light should be treated as a composite. The main colors are from purple to red. This experiment of Newton serves as a wonderful example of how different people, observing the same phenomenon, interpret it in different ways, and only those who question their interpretation and set up additional experiments come to the correct conclusions.

7. Thomas Young's experiment

Until the beginning of the 19th century, ideas about the corpuscular nature of light prevailed. Light was considered to be composed of individual particles - corpuscles. Although the phenomena of diffraction and interference of light were observed by Newton ("Newton's rings"), the generally accepted point of view remained corpuscular. Considering the waves on the water surface from two thrown stones, one can see how, superimposing on each other, the waves can interfere, that is, mutually suppress or mutually reinforce each other. Based on this, the English physicist and physician Thomas Jung made experiments in 1801 with a beam of light that passed through two holes in an opaque screen, thus forming two independent sources of light, similar to two stones thrown into water. As a result, he observed an interference pattern consisting of alternating dark and white stripes, which could not have formed if the light consisted of corpuscles. The dark stripes corresponded to the areas where the light waves from the two slits extinguish each other. Light streaks appeared where the light waves reinforced. Thus, the wave nature of light was proved.

8. Klaus Jonsson's experiment

German physicist Klaus Jonsson conducted an experiment similar to Thomas Jung's experiment on the interference of light in 1961. The difference was that instead of beams of light, Jonsson used beams of electrons. He obtained an interference pattern similar to that which Jung observed for light waves. This confirmed the correctness of the provisions of quantum mechanics about the mixed wave-particle nature of elementary particles.

9. Experiment by Robert Millikan

The idea that the electric charge of any body is discrete (that is, it consists of a larger or smaller set of elementary charges that are no longer subject to fragmentation) arose at the beginning of the 19th century and was supported by such famous physicists as M. Faraday and G. Helmholtz. The term "electron" was introduced into the theory, denoting a certain particle - the carrier of an elementary electric charge. This term, however, was at that time purely formal, since neither the particle itself, nor the elementary electric charge associated with it were discovered experimentally.

In 1895, K. Roentgen, during experiments with a discharge tube, discovered that its anode, under the action of rays flying from the cathode, is capable of emitting its own, X-rays, or X-rays. In the same year, the French physicist J. Perrin experimentally proved that cathode rays are a stream of negatively charged particles. But, despite the colossal experimental material, the electron remained a hypothetical particle, since there was not a single experiment in which individual electrons would participate. The American physicist Robert Millikan developed a method that became a classic example of an elegant physical experiment.

Millikan managed to isolate in space several charged water droplets between the condenser plates. By illuminating with X-rays, it was possible to slightly ionize the air between the plates and change the charge of the droplets. When the field was switched on between the plates, the droplet slowly moved upward under the action of electric attraction. With the field turned off, it descended under the influence of gravity. Turning the field on and off, it was possible to study each of the droplets suspended between the plates for 45 seconds, after which they evaporated. By 1909, it was possible to determine that the charge of any droplet was always an integer multiple of the fundamental value e (electron charge). This was compelling evidence that electrons were particles with the same charge and mass. Replacing water droplets with oil droplets, Millikan was able to increase the duration of observations to 4.5 hours and in 1913, eliminating one after another possible sources of error, published the first measured value of the electron charge: e = (4.774 ± 0.009) x 10-10 electrostatic units.

10. Ernst Rutherford's experiment

By the beginning of the 20th century, it became clear that atoms are composed of negatively charged electrons and some kind of positive charge, due to which the atom remains generally neutral. However, there were too many assumptions about what this "positive-negative" system looks like, while the experimental data that would make it possible to make a choice in favor of one model or another were clearly lacking.

Most physicists have adopted the model of J.J. Thomson: an atom as a uniformly charged positive sphere with a diameter of about 10-8 cm with negative electrons floating inside. In 1909, Ernst Rutherford (assisted by Hans Geiger and Ernst Marsden) set up an experiment to understand the actual structure of the atom. In this experiment, heavy positively charged a-particles moving at a speed of 20 km / s passed through a thin gold foil and were scattered by gold atoms, deviating from the original direction of motion. To determine the degree of deflection, Geiger and Marsden had to use a microscope to observe the flashes on the scintillator plate, which occurred where the a-particle entered the plate. Over two years, about a million flares were counted and it was proved that about one particle in 8000, as a result of scattering, changes direction by more than 90 ° (that is, turns back). This could not have happened in Thomson's "loose" atom. The results unequivocally testified in favor of the so-called planetary model of the atom - a massive tiny nucleus about 10-13 cm in size and electrons orbiting this nucleus at a distance of about 10-8 cm.

In school physics lessons, teachers always say that physical phenomena are everywhere in our lives. Only we often forget about it. Meanwhile, the amazing is near! Don't feel like you need something supernatural to organize physical experiences at home. And here is some evidence for you;)

Magnetic pencil

What needs to be prepared?

• Battery.
• Thick pencil.
• Insulated copper wire 0.2–0.3 mm in diameter and several meters long (the more, the better).
• Scotch.

Experiment

Wrap the wire close to the loop on the pencil, not reaching its edges by 1 cm. One row is over - wind the other on top in the opposite direction. And so, until all the wire runs out. Do not forget to leave free two ends of the wire, 8–10 cm each. To prevent the coils from unwinding after winding, secure them with tape. Strip the free ends of the wire and connect them to the battery contacts.

What happened?

It turned out to be a magnet! Try to bring small iron objects to it - a paper clip, hairpin. Are attracted!

Lord of water

What needs to be prepared?

• A plexiglass stick (for example, a student's ruler or an ordinary plastic comb).
• Dry cloth made of silk or wool (for example, woolen sweater).

Experiment

Open the tap for a thin stream of water to flow. Rub your wand or comb vigorously on the prepared cloth. Move the stick quickly to the stream of water without touching it.

What's going to happen?

The stream of water will bend in an arc, being attracted to the stick. Try the same thing with two sticks and see what happens.

Spinning top

What needs to be prepared?

• Paper, needle and eraser.
• Stick and dry woolen cloth from previous experience.

Experiment

You can control not only water! Cut a strip of paper 1–2 cm wide and 10–15 cm long, and bend around the edges and in the middle as shown. Insert the sharp end of the needle into the eraser. Balance the top on the needle. Prepare the "magic wand", rub it on a dry cloth and bring it to one of the ends of the paper strip from the side or top, without touching it.

What's going to happen?

The strip will swing up and down like a swing, or it will spin like a carousel. And if you can cut a butterfly out of thin paper, then the experience will be even more interesting.

Ice and flames

(the experiment is carried out on a sunny day)

What needs to be prepared?

• A small round bottom cup.
• A piece of dry paper.

Experiment

Pour water into a cup and place in the freezer. When the water turns to ice, remove the cup and place it in a container of hot water. After a while, the ice will separate from the cup. Now go out to the balcony, put a piece of paper on the stone floor of the balcony. Use a piece of ice to focus the sun on the piece of paper.

What's going to happen?

The paper should be charred, because there is more than just ice in your hands ... You guessed that you made a magnifying glass?

Wrong mirror

What needs to be prepared?

• A transparent jar with a tight-fitting lid.
• Mirror.

Experiment

Pour an excess of water into the jar and close the lid to prevent air bubbles from getting inside. Place the jar upside down to the mirror. Now you can look in the "mirror".

Zoom into your face and look inside. There will be a thumbnail image. Now start tilting the can to the side without lifting it from the mirror.

What's going to happen?

The reflection of your head in the can, of course, will also tilt until it is turned upside down, while the legs will not be visible. Pick up the can and the reflection flips over again.

Bubble cocktail

What needs to be prepared?

• A glass with a strong solution of sodium chloride.
• Flashlight battery.
• Two pieces of copper wire approximately 10 cm long.
• Fine sandpaper.

Experiment

Sand the ends of the wire with a fine emery cloth. Connect one end of the wires to each pole of the battery. Dip the free ends of the wires into a glass with a solution.

What happened?

Bubbles will rise near the lowered ends of the wire.

Lemon battery

What needs to be prepared?

• Lemon, thoroughly washed and wiped dry.
• Two pieces of insulated copper wire, approximately 0.2–0.5 mm thick and 10 cm long.
• A steel paper clip.
• A light bulb from a pocket flashlight.

Experiment

Strip the opposite ends of both wires at a distance of 2-3 cm. Insert a paper clip into the lemon, screw the end of one of the wires to it. Stick the end of the second wire into the lemon 1–1.5 cm from the paper clip. To do this, first pierce the lemon in this place with a needle. Take the two free ends of the wires and attach the light bulb to the contacts.

What's going to happen?

The light will come on!