Physics experiments for little ones. Various physical experiments

For many schoolchildren, physics is a rather complex and incomprehensible subject. To interest a child in this science, parents use all sorts of tricks: they tell fantasy stories, show interesting experiments, cite biographies of great scientists as examples.

How to conduct physics experiments with children?

• Teachers warn that it is not worth getting acquainted with physical phenomena limit it only to the demonstration of entertaining experiences and experiments.
• Experiments must be accompanied by detailed explanations.
• First, you need to explain to the child that physics is a science that studies general laws nature. Physics studies the structure of matter, its forms, its movements and changes. At one time, the famous British scientist Lord Kelvin quite boldly stated that in our world there is only one science - physics, everything else is ordinary stamp collecting. And there is some truth in this statement, because the entire Universe, all planets and all worlds (alleged and existing) obey the laws of physics. Of course, the statements of the most eminent scientists about physics and its laws are unlikely to force a junior school student to throw aside his mobile phone and enthusiastically delve into the study of a physics textbook.

Today we will try to bring to the attention of parents several entertaining experiences that will help interest your children and answer many of their questions. And who knows, maybe thanks to these home experiments, physics will become your child’s favorite subject. And very soon our country will have its own Isaac Newton.

Interesting experiments with water for children - 3 instructions

For 1 experiment you will need two eggs, regular table salt and 2 glasses of water.

One egg must be carefully lowered into a glass half full cold water. It will immediately end up at the bottom. Fill the second glass warm water and stir 4-5 tbsp in it. l. salt. Wait until the water in the glass becomes cold and carefully lower the second egg into it. It will remain on the surface. Why?

Explanation of experimental results

The density of plain water is lower than that of an egg. This is why the egg sinks to the bottom. The average density of salt water is significantly higher than the density of an egg, so it remains on the surface. Having demonstrated this experience to a child, you can notice that sea ​​water is an ideal environment for learning to swim. After all, no one has canceled the laws of physics even at sea. The saltier the sea water, the less effort is required to stay afloat. The Red Sea is considered the saltiest. Due to the high density, the human body is literally pushed to the surface of the water. Learning to swim in the Red Sea is a real pleasure.

For experiment 2 you will need: Glass bottle, a bowl of colored water and hot water.

Using hot water, warm up the bottle. Let's pour it out hot water and turn it upside down. Place in a bowl of tinted cold water. The liquid from the bowl will begin to flow into the bottle on its own. By the way, the level of colored liquid in it will be (compared to a bowl) significantly higher.

How to explain the result of the experiment to a child?

The pre-heated bottle is filled with warm air. Gradually the bottle cools and the gas contracts. The pressure in the bottle decreases. The water is influenced by atmospheric pressure and flows into the bottle. Its inflow will stop only when the pressure does not equalize.

For 3 experiences You will need a plexiglass ruler or a regular plastic comb, wool or silk fabric.

In the kitchen or bathroom, adjust the faucet so that a thin stream of water flows from it. Ask your child to rub the ruler (comb) vigorously with a dry woolen cloth. Then the child must quickly bring the ruler closer to the stream of water. The effect will amaze him. The stream of water will bend and reach towards the ruler. A funny effect can be achieved by using two rulers at the same time. Why?

An electrified dry comb or plexiglass ruler becomes a source electric field, which is why the jet is forced to bend in its direction.

You can learn more about all these phenomena in physics lessons. Any child will want to feel like the “master” of water, which means that the lesson will never be boring and uninteresting for him.

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How can you prove that light travels in a straight line?

To conduct the experiment, you will need 2 sheets of thick cardboard, a regular flashlight, and 2 stands.

Progress of the experiment: In the center of each cardboard, carefully cut out round holes of equal diameter. We install them on stands. The holes must be at the same height. We place the switched-on flashlight on a pre-prepared stand made of books. You can use any box of suitable size. We direct the flashlight beam into the hole of one of the cardboards. The child stands on the opposite side and sees the light. We ask the child to move away and move any of the cardboards to the side. Their holes are no longer at the same level. We return the child to the same place, but he no longer sees the light. Why?

Explanation: Light can only travel in a straight line. If there is an obstacle in the path of the light, it stops.

Experience - Dancing Shadows

To carry out this experiment you will need: a white screen, cut out cardboard figures that need to be hung on strings in front of the screen and regular candles. Candles need to be placed behind the figures. No screen - you can use a regular wall

Progress of the experiment: Light the candles. If the candle is moved further away, the shadow of the figure will become smaller; if the candle is moved to the right, the figure will move to the left. The more candles you light, the more interesting the dance of the figures will be. Candles can be lit one at a time, raised higher or lower, creating very interesting dance compositions.

Interesting experience with shadow

For the next experiment you will need a screen, a fairly powerful electric lamp and a candle. If you direct the light of a powerful electric lamp onto a burning candle, then a shadow will appear on the white canvas not only from the candle, but also from its flame. Why? It’s simple, it turns out that in the flame itself there are red-hot, light-proof particles.

Simple experiments with sound for younger students

Ice experiment

If you are lucky and find a piece of dry ice at home, you may hear an unusual sound. It is quite unpleasant - very thin and howling. To do this, put dry ice in a regular teaspoon. True, the spoon will immediately stop sounding as soon as it cools down. Why does this sound appear?

When ice comes into contact with a spoon (in accordance with the laws of physics), it releases carbon dioxide, it is he who makes the spoon vibrate and make an unusual sound.

funny phone

Take two identical boxes. Poke a hole in the middle of the bottom and lid of each box using a thick needle. Place regular matches in the boxes. Thread a cord (10-15 cm long) into the holes made. Each end of the lace must be tied in the middle of the match. It is advisable to use a nylon fishing line or silk thread. Each of the two participants in the experiment takes his “tube” and moves to the maximum distance. The line should be taut. One puts the tube to the ear and the other to the mouth. That's all! The phone is ready - you can have small talk!

Echo

Make a pipe out of cardboard. Its height should be about three hundred mm and its diameter about sixty mm. Place the clock on a regular pillow and cover it on top with a pre-made pipe. In this case, you can hear the sound of the clock if your ear is directly above the pipe. In all other positions the sound of the clock is not audible. However, if you take a piece of cardboard and place it at an angle of forty-five degrees to the axis of the pipe, then the sound of the clock will be perfectly audible.

How to conduct experiments with magnets at home with your child - 3 ideas

Children simply love to play with magnets, so they are ready to get involved in any experiment with this item.

How to pull objects out of water using a magnet?

For the first experiment you will need a lot of bolts, paper clips, springs, a plastic bottle with water and a magnet.

The children are given the task: to pull objects out of the bottle without getting their hands wet, and of course the table. As a rule, children quickly find a solution to this problem. During the experiment, parents can tell their children about physical properties magnet and explain that the force of a magnet acts not only through plastic, but also through water, paper, glass, etc.

How to make a compass?

You need to collect in a saucer cold water and place a small piece of napkin on its surface. We carefully place a needle on a napkin, which we first rub on the magnet. The napkin gets wet and sinks to the bottom of the saucer, and the needle remains on the surface. Gradually it smoothly turns one end to the north, the other to the south. The accuracy of a homemade compass can be verified for real.

A magnetic field

To begin, draw a straight line on a piece of paper and place a regular iron clip on it. Slowly move the magnet towards the line. Mark the distance at which the paperclip will be attracted to the magnet. Take another magnet and do the same experiment. The paperclip will be attracted to the magnet from a further distance or from a closer one. Everything will depend solely on the “strength” of the magnet. Using this example, you can tell your child about the properties of magnetic fields. Before telling your child about the physical properties of a magnet, you must explain that a magnet does not attract all “shiny things.” A magnet can only attract iron. Metals such as nickel and aluminum are too tough for him.

I wonder if you liked physics lessons at school? No? Then you have a great opportunity to master this very interesting subject together with your child. Find out how to spend interesting and simple ones at home, read another article on our website.

Good luck with your experiments!

From the book "My First Experiences."

Lung volume

For the experience you need:

adult assistant;
large plastic bottle;
washing basin;
water;
plastic hose;
beaker.

1. How much air can your lungs hold? To find out, you'll need the help of an adult. Fill the bowl and bottle with water. Have an adult hold the bottle upside down under water.

2. Insert a plastic hose into the bottle.

3. Take a deep breath and blow into the hose as hard as you can. Air bubbles will appear in the bottle rising up. Clamp the hose as soon as the air in your lungs runs out.

4. Pull out the hose and ask your assistant, covering the neck of the bottle with his palm, to turn it over to the correct position. To find out how much gas you exhaled, add water to the bottle using a measuring cup. See how much water you need to add.

Make it rain

For the experience you need:

adult assistant;
fridge;
Electric kettle;
water;
metal spoon;
saucer;
potholder for hot dishes.

1. Place the metal spoon in the refrigerator for half an hour.

2. Ask an adult to help you do the experiment from beginning to end.

3. Boil a full kettle of water. Place a saucer under the spout of the teapot.

4. Using an oven mitt, carefully move the spoon toward the steam rising from the spout of the kettle. When the steam hits a cold spoon, it condenses and “rains” onto the saucer.

Make a hygrometer

For the experience you need:

2 identical thermometers;
cotton wool;
round rubber bands;
empty yogurt cup;
water;
large cardboard box without lid;
spoke.

1. Using a knitting needle, poke two holes in the wall of the box at a distance of 10 cm from each other.

2. Wrap two thermometers with the same amount of cotton wool and secure with rubber bands.

3. Tie an elastic band on top of each thermometer and thread the elastic bands into the holes at the top of the box. Insert a knitting needle into the rubber loops as shown in the figure so that the thermometers hang freely.

4. Place a glass of water under one thermometer so that the water wets the cotton wool (but not the thermometer).

5. Compare thermometer readings in different time days. The greater the temperature difference, the lower the air humidity.

Call the cloud

For the experience you need:

transparent glass bottle;
hot water;
ice Cube;
dark blue or black paper.

1. Fill the bottle carefully hot water.

2. After 3 minutes, pour out the water, leaving a little at the very bottom.

3. Place on top of the neck open bottle ice Cube.

4. Place a sheet of dark paper behind the bottle. Where the hot air rising from the bottom comes into contact with the cooled air at the neck, a white cloud forms. Water vapor in the air condenses, forming a cloud of tiny water droplets.

Under pressure

For the experience you need:

transparent plastic bottle;
large bowl or deep tray;
water;
coins;
strip of paper;
pencil;
ruler;
adhesive tape.

1. Fill the bowl and bottle halfway with water.

2. Draw a scale on a strip of paper and stick it to the bottle with adhesive tape.

3. Place two or three small stacks of coins in the bottom of the bowl, large enough to fit the neck of the bottle. Thanks to this, the neck of the bottle will not rest against the bottom, and water will be able to freely flow out of the bottle and flow into it.

4. Plug the neck of the bottle with your thumb and carefully place the bottle upside down on the coins.

Your water barometer will allow you to monitor changes in atmospheric pressure. As the pressure increases, the water level in the bottle will rise. When the pressure drops, the water level will drop.

Make an air barometer

For the experience you need:

wide mouth jar;
balloon;
scissors;
rubber band;
drinking straw;
cardboard;
pen;
ruler;
adhesive tape.

1. Cut the balloon and pull it tightly onto the jar. Secure with an elastic band.

2. Sharpen the end of the straw. Glue the other end to the stretched ball with adhesive tape.

3. Draw a scale on a cardboard card and place the cardboard at the end of the arrow. When Atmosphere pressure grows, the air in the jar is compressed. When it falls, the air expands. Accordingly, the arrow will move along the scale.

If the pressure rises, the weather will be fine. If it falls, it's bad.

What gases does air consist of?

For the experience you need:

adult assistant;
glass jar;
candle;
water;
coins;
large glass bowl.

1. Have an adult light a candle and add paraffin to the bottom of the bowl to secure the candle.

2. Carefully fill the bowl with water.

3. Cover the candle with a jar. Place stacks of coins under the jar so that its edges are only slightly below the water level.

4. When all the oxygen in the jar has burned out, the candle will go out. The water will rise, occupying the volume where oxygen used to be. So you can see that there is about 1/5 (20%) oxygen in the air.

Make a battery

For the experience you need:

durable paper towel;
food foil;
scissors;
copper coins;
salt;
water;
two insulated copper wires;
small light bulb.

1. Dissolve a little salt in water.

2. Cut the paper towel and foil into squares slightly larger than coins.

3. Wet the paper squares in salt water.

4. Place on top of each other in a stack: copper coin, a piece of foil, a piece of paper, a coin again, and so on several times. There should be paper on top of the stack and a coin on the bottom.

5. Slide the stripped end of one wire under the stack, and connect the other end to the light bulb. Place one end of the second wire on top of the stack, and also connect the other to the light bulb. What happened?

solar fan

For the experience you need:

food foil;
black paint or marker;
scissors;
adhesive tape;
threads;
large clean glass jar with lid.

1. Cut two strips of foil, each approximately 2.5 x 10 cm in size. Color one side with a black marker or paint. Make slits in the strips and insert them one into the other, bending the ends, as shown in the figure.

2. Using thread and duct tape, attach the solar panels to the lid of the jar. Place the jar in sunny place. The black side of the strips heats up more than the shiny side. Due to the temperature difference, there will be a difference in air pressure and the fan will begin to rotate.

What color is the sky?

For the experience you need:

glass beaker;
water;
tea spoon;
flour;
white paper or cardboard;
flashlight.

1. Stir half a teaspoon of flour in a glass of water.

2. Place the glass on white paper and shine a flashlight on it from above. The water appears light blue or gray.

3. Now place the paper behind the glass and shine the light on it from the side. The water appears pale orange or yellowish.

The smallest particles in the air, like flour in water, change the color of light rays. When the light comes from the side (or when the sun is low on the horizon), the blue color is scattered and the eye sees an excess of orange rays.

Make a mini microscope

For the experience you need:

small mirror;
plasticine;
glass beaker;
aluminium foil;
needle;
adhesive tape;
drop of oxen;
small flower

1. A microscope uses a glass lens to refract a ray of light. A drop of water can fulfill this role. Place the mirror at an angle on a piece of plasticine and cover it with a glass.

2. Fold the aluminum foil like an accordion to create a multi-layered strip. Carefully make a small hole in the center with a needle.

3. Bend the foil over the glass as shown in the picture. Secure the edges with adhesive tape. Using the tip of your finger or needle, drop water onto the hole.

4. Place a small flower or other small item on the bottom of the glass under the water lens. A homemade microscope can magnify it almost 50 times.

Call the lightning

For experience you need:

metal baking tray;
plasticine;
plastic bag;
metal fork.

1. Press a large piece of plasticine onto a baking sheet to form a handle. Now don't touch the pan itself - just the handle.

2. Holding the baking sheet by the plasticine handle, rub it in a circular motion against the bag. At the same time, static accumulates on the baking sheet. electric charge. The baking sheet should not extend beyond the edges of the bag.

3. Lift the baking sheet slightly above the bag (still holding onto the plasticine handle) and bring the tines of a fork to one corner. A spark will jump from the baking sheet to the fork. This is how lightning jumps from a cloud to a lightning rod.

Most people, remembering their school years, we are sure that physics is a very boring subject. The course includes many problems and formulas that will not be useful to anyone in later life. On the one hand, these statements are true, but, like any subject, physics has another side to the coin. But not everyone discovers it for themselves.

A lot depends on the teacher

Perhaps our education system is to blame for this, or maybe it’s all about the teacher who thinks only about the need to teach the material approved from above and does not strive to interest his students. Most often it is he who is to blame. However, if the children are lucky and the lesson is taught by a teacher who loves his subject, he will not only be able to interest the students, but will also help them discover something new. As a result, children will begin to enjoy attending such classes. Of course, formulas are an integral part of this academic subject, there is no escape from this. But there are also positive aspects. Experiments are of particular interest to schoolchildren. This is what we will talk about in more detail. We'll look at some fun physics experiments you can do with your child. This should be interesting not only to him, but also to you. It is likely that with the help of such activities you will instill in your child a genuine interest in learning, and “boring” physics will become his favorite subject. It’s not at all difficult to carry out, it will require very few attributes, the main thing is that there is a desire. And perhaps then you will be able to replace your child’s school teacher.

Let's look at some interesting experiments in physics for little ones, because you need to start small.

Paper fish

To conduct this experiment, we need to cut out a small fish from thick paper (can be cardboard), the length of which should be 30-50 mm. We make a round hole in the middle with a diameter of approximately 10-15 mm. Next, from the side of the tail, we cut a narrow channel (width 3-4 mm) to a round hole. Then we pour water into the basin and carefully place our fish there so that one plane lies on the water, and the second remains dry. Now you need to drop some oil into the round hole (you can use an oil can from sewing machine or bicycle). The oil, trying to spread over the surface of the water, will flow through the cut channel, and the fish will swim forward under the influence of the oil flowing back.

Elephant and Moska

Let's continue to conduct entertaining experiments in physics with our child. We invite you to introduce your child to the concept of a lever and how it helps make a person’s work easier. For example, tell us that it can be used to easily lift a heavy cabinet or sofa. And for clarity, show a basic experiment in physics using a lever. For this we will need a ruler, a pencil and a couple of small toys, but be sure to different weights(that’s why we called this experience “Elephant and Pug”). We attach our Elephant and Pug to different ends of the ruler using plasticine or ordinary thread (we just tie the toys). Now, if you put a ruler middle part on a pencil, then, of course, the elephant will pull it, because it is heavier. But if you move the pencil towards the elephant, then Moska will easily outweigh it. This is the principle of leverage. The ruler (lever) rests on the pencil - this place is the fulcrum. Next, the child should be told that this principle is used everywhere; it is the basis for the operation of a crane, swing, and even scissors.

Home experiment in physics with inertia

We will need a jar of water and a utility net. It will be no secret to anyone that if open jar turn it over, the water will pour out of it. Let's try? Of course, it’s better to go outside for this. We put the can in the net and begin to swing it smoothly, gradually increasing the amplitude, and as a result we make a full revolution - one, two, three, and so on. Water does not pour out. Interesting? Now let's make the water pour out. To do this, take a tin can and make a hole in the bottom. We put it in the net, fill it with water and start rotating. A stream comes out of the hole. When the can is in the lower position, this does not surprise anyone, but when it flies up, the fountain continues to flow in the same direction, and not a drop comes out of the neck. That's it. All this can be explained by the principle of inertia. When rotating, the can tends to fly straight away, but the mesh does not let it go and forces it to describe circles. Water also tends to fly by inertia, and in the case when we have made a hole in the bottom, there is nothing stopping it from breaking out and moving in a straight line.

Box with a surprise

Now let's look at physics experiments with displacement. You need to put a matchbox on the edge of the table and slowly move it. The moment it passes its average mark, a fall will occur. That is, the mass of the part pushed over the edge of the table top will exceed the weight of the remaining part, and the box will tip over. Now let's shift the center of mass, for example, put a metal nut inside (as close to the edge as possible). All that remains is to place the box in such a way that a small part of it remains on the table, and a large part hangs in the air. There will be no fall. The essence of this experiment is that the entire mass is above the fulcrum. This principle is also used throughout. It is thanks to him that furniture, monuments, transport, and much more are in a stable position. By the way, the children's toy Vanka-Vstanka is also built on the principle of shifting the center of mass.

So, let's continue to look at interesting experiments in physics, but let's move on to the next stage - for sixth-grade students.

Water carousel

We will need an empty tin can, a hammer, a nail, and a rope. We use a nail and a hammer to punch a hole in the side wall near the bottom. Next, without pulling the nail out of the hole, bend it to the side. It is necessary that the hole is oblique. We repeat the procedure on the second side of the can - you need to make sure that the holes are opposite each other, but the nails are bent in different sides. We punch two more holes in the upper part of the vessel and thread the ends of a rope or thick thread into them. We hang the container and fill it with water. Two oblique fountains will begin to flow from the lower holes, and the jar will begin to rotate in the opposite direction. I work on this principle space rockets- the flame from the engine nozzles shoots in one direction, and the rocket flies in the other.

Experiments in physics - 7th grade

Let's conduct an experiment with mass density and find out how you can make an egg float. Physics experiments with different densities are best done using fresh and salt water as an example. Take a jar filled with hot water. Drop an egg into it and it will immediately sink. Next, add table salt to the water and stir. The egg begins to float, and the more salt, the higher it will rise. This is because salt water has a higher density than fresh water. So, everyone knows that in the Dead Sea (its water is the saltiest) it is almost impossible to drown. As you can see, experiments in physics can significantly expand your child’s horizons.

and a plastic bottle

Seventh grade students begin to study atmospheric pressure and its effect on the objects around us. To explore this topic deeper, it is better to conduct appropriate experiments in physics. Atmospheric pressure affects us, although it remains invisible. Let's give an example with balloon. Each of us can cheat it. Then we will place it in plastic bottle, put the edges on the neck and fix it. This way, air can only flow into the ball, and the bottle will become a sealed container. Now let's try to inflate the balloon. We will not succeed, since the atmospheric pressure in the bottle will not allow us to do this. When we blow, the ball begins to displace the air in the container. And since our bottle is sealed, it has nowhere to go, and it begins to shrink, thereby becoming much denser than the air in the ball. Accordingly, the system is leveled, and it is impossible to inflate the balloon. Now we’ll make a hole in the bottom and try to inflate the balloon. In this case, there is no resistance, the displaced air leaves the bottle - the atmospheric pressure is equalized.

Conclusion

As you can see, the physics experiments are not at all complicated and quite interesting. Try to interest your child - and his studies will be completely different, he will begin to attend classes with pleasure, which will ultimately affect his performance.

Many people think that science is boring and dreary. This is the opinion of those who have not seen the science shows from Eureka. What happens in our “lessons”? No cramming, tedious formulas and sour expression on the face of your desk neighbor. Our science, all experiments and experiences are liked by children, our science is loved, our science gives joy and stimulates further knowledge of complex subjects.

Try it yourself and conduct entertaining physics experiments for children at home. It will be fun, and most importantly, very educational. Your child is in game form get acquainted with the laws of physics, but it has been proven that when playing, children learn the material faster and easier and remember it for a long time.

Entertaining physics experiments worth showing your children at home

Simple, entertaining physics experiments that children will remember for a lifetime. Everything you need to conduct these experiments is at your fingertips. So, forward to scientific discoveries!

A ball that doesn't burn!

Props: 2 balloons, candle, matches, water.

Interesting experience: We inflate the first balloon and hold it over a candle to demonstrate to the children that the fire will burst the balloon.

Pour plain tap water into the second ball, tie it and bring the candles to the fire again. And lo and behold! What do we see? The ball doesn't burst!

The water in the ball absorbs the heat generated by the candle, and therefore the ball does not burn, and therefore does not burst.

Miracle pencils

Requisites: plastic bag, regular sharpened pencils, water.

Interesting experience: Pour water into a plastic bag - not full, half.

In the place where the bag is filled with water, we pierce the bag right through with pencils. What do we see? In places of puncture, the bag does not leak. Why? But if you do the opposite: first pierce the bag and then pour water into it, the water will flow through the holes.

How a “miracle” happens: explanation: When polyethylene breaks, its molecules are attracted closer friend to friend. In our experiment, the polyethylene tightens around the pencils and prevents water from leaking.

Unbreakable balloon

Requisites: balloon, wooden skewer and dishwashing liquid.

Interesting experience: Lubricate the top and bottom of the ball with dishwashing liquid and pierce it with a skewer, starting from the bottom.

How a “miracle” happens: explanation: And the secret of this “trick” is simple. To preserve the whole ball, you need to know where to pierce - at the points of least tension, which are located at the bottom and top of the ball.

"Cauliflower

Requisites: 4 ordinary glasses of water, bright food colors, cabbage leaves or white flowers.

Interesting experience: Add food coloring of any color to each glass and place in colored water one cabbage leaf or flower. We leave the “bouquet” overnight. And in the morning... we will see that the cabbage leaves or flowers have become different colors.

How a “miracle” happens: explanation: Plants absorb water to nourish their flowers and leaves. This occurs due to the capillary effect, in which water itself fills thin tubes inside the plants. By sucking up the tinted water, the leaves and color change.

The egg that could swim

Requisites: 2 eggs, 2 glasses of water, salt.

Interesting experience: Carefully place the egg in a glass with regular clean water. We see: it has drowned, sank to the bottom (if not, the egg is rotten and it is better to throw it away).
But pour it into the second glass warm water and stir in 4-5 tablespoons of salt. We wait until the water cools down, then lower it into salt water second egg. And what do we see now? The egg floats on the surface and does not sink! Why?

How a “miracle” happens: explanation: It's all about density! The average density of an egg is much greater than the density of plain water, so the egg “sinks.” A density saline solution more, and therefore the egg “floats”.

Delicious experiment: crystal candies

Requisites: 2 glasses of water, 5 glasses of sugar, wooden sticks for mini-kebabs, thick paper, transparent glasses, pan, food coloring.

Interesting experience: Take a quarter glass of water, add 2 tablespoons of sugar, and cook the syrup. At the same time, pour a little sugar onto thick paper. Then dip a wooden skewer into the syrup and collect the sugar with it.

Let the sticks dry overnight.

In the morning, dissolve 5 cups of sugar in two glasses of water, leave the syrup to cool for 15 minutes, but not too much, otherwise the crystals will not “grow.” Then pour the syrup into jars and add multi-colored food coloring. We lower the skewers with sugar into the jars so that they do not touch either the walls or the bottom (you can use a clothespin). What's next? And then we watch the process of crystal growth, wait for the result so that... we can eat it!

How the “miracle” happens: explanation: As soon as the water begins to cool, the solubility of sugar decreases and it precipitates, settling on the walls of the vessel and on a skewer seeded with sugar grains.

"Eureka"! Science without boredom!

There is another option to motivate children to study science - order a science show at the Eureka development center. Oh, what’s not here!

Show program “Fun Kitchen”

Here, children can enjoy exciting experiments with things and products that are available in any kitchen. The kids will try to drown the mandarin duck; make drawings on milk, check the egg for freshness, and also find out why milk is healthy.

"Tricks"

This program contains experiments that at first glance seem like real magic tricks, but in fact they are all explained using science. The kids will find out why a balloon over a candle doesn’t burst; what makes an egg float, why a balloon sticks to the wall... and other interesting experiments.

« Entertaining physics»

Does air weigh, why does a fur coat keep you warm, what is common between the experiment with a candle and the shape of the wings of birds and airplanes, can a piece of fabric hold water, can it withstand eggshell Kids will get an answer to these and other questions by becoming a participant in the “Entertaining Physics” show from “Eureka”.

These Entertaining experiments in physics for schoolchildren can be carried out in lessons to attract students’ attention to the phenomenon being studied, during repetition and consolidation educational material: they deepen and expand the knowledge of schoolchildren, contribute to the development logical thinking, instill interest in the subject.

This is important: science show safety

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Tens and hundreds of thousands of physical experiments have been carried out over the thousand-year history of science. It’s not easy to select a few of the “best” to talk about. What should be the selection criterion?

Four years ago in the newspaper " The New York Times" an article by Robert Creese and Stoney Book was published. It reported on the results of a survey conducted among physicists. Each respondent had to name the ten most beautiful physics experiments in the entire history. In our opinion, the criterion of beauty is in no way inferior to other criteria. Therefore we will talk about the experiments that were included in the top ten according to the results of the Kreese and Book survey.

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, Erastothenes of Cyrene.

The experimental design is simple. At noon, on the day summer solstice, in the city of Siena (now Aswan) the Sun was at its zenith and objects did not cast shadows. 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 approximately 7°. This is approximately 1/50 full circle(360°), which means that the circumference of the Earth is 40,000 kilometers and the radius is 6,300 kilometers.

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

2. Galileo Galilei's experiment

In the 17th century, the dominant point of view was Aristotle, who taught that the speed at which a body falls depends on its mass. The heavier the body, the faster it falls. Observations that each of us can make in Everyday life, would seem to confirm this.

Try letting go of 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 speed of falling is affected 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 ones is different, which leads to the observed effect. The Italian Galileo Galilei doubted 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, for both the core and the bullet, the air resistance forces were negligible compared to the forces of gravity.

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

3. Another Galileo Galilei experiment

Galileo measured the distance that balls rolling on an inclined board covered in equal intervals of time, measured by the author of the experiment using a water clock. The scientist found that if the time was doubled, the balls would roll four times further. This quadratic relationship meant that the balls moved at an accelerated rate under the influence of gravity, which contradicted Aristotle's assertion, which had been accepted for 2000 years, that bodies on which a force acts move at a constant speed, whereas if no force is applied to the body, then it is at rest.

The results of this experiment by 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 Mit, separated from each other by a distance r, 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 force of attraction is very small.

We feel the force of gravity of the Earth. But it is impossible to feel the attraction of even a very large mountain nearby, since it is very weak. A very subtle and sensitive method was needed. It was invented and used in 1798 by Newton's compatriot Henry Cavendish. He used a torsion scale - a rocker with two balls suspended on a very thin cord. Cavendish measured the displacement of the rocker arm (rotation) as other balls of greater mass approached the scales.

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

5. Jean Bernard Foucault's experiment

French physicist Jean Bernard Leon Foucault experimentally proved the rotation of the Earth around its axis in 1851 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. An observer located on the Earth and rotating with it sees that the plane of rotation is slowly turning to the side, opposite direction rotation of the Earth.

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 he passed Sunbeam. 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 ray of sunlight, 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 single crystals natural origin have the property of breaking light into colors. The first studies of light dispersion in experiments with a glass triangular prism, even before Newton, were carried out by the Englishman Hariot and the Czech naturalist Marzi.

However, before Newton, such observations were not subjected to serious analysis, and the conclusions drawn on their basis were not cross-checked by additional experiments. Both Hariot and Marzi remained followers of Aristotle, who argued that differences in color are determined by differences in the amount of darkness “mixed” with white light. Purple, according to Aristotle, arises with the greatest addition of darkness to light, and red with the least. Newton carried out additional experiments with crossed prisms, when light passed through one prism then passes through another. Based on the totality of his experiments, he concluded that “no color arises from white and black mixed together, except the intermediate dark ones; the amount of light does not change the appearance of the color.” He showed that white light should be considered as a compound. The main colors are from purple to red. This Newton experiment serves wonderful example as different people, observing the same phenomenon, interpret it in different ways, and only those who question their interpretation and carry out 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 consist 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. Looking at the waves on the surface of the water from two thrown stones, you can see how, overlapping each other, the waves can interfere, that is, cancel out or mutually reinforce each other. Based on this, the English physicist and physician Thomas Young conducted experiments in 1801 with a beam of light that passed through two holes in an opaque screen, thus forming two independent light sources, similar to two stones thrown into water. As a result, he observed an interference pattern consisting of alternating dark and white fringes, which could not be formed if light consisted of corpuscles. The dark stripes corresponded to areas where light waves from the two slits cancel each other out. Light stripes appeared where light waves mutually reinforced each other. Thus, the wave nature of light was proven.

8. Klaus Jonsson's experiment

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

9. Robert Millikan's experiment

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 back in early XIX 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 purely formal at that time, since neither the particle itself nor the elementary electric charge associated with it had been discovered experimentally.

In 1895, K. Roentgen, during experiments with a discharge tube, discovered that its anode, under the influence of rays flying from the cathode, was capable of emitting its own X-rays, or Roentgen rays. In the same year, 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. American physicist Robert Millikan developed a method that has become a classic example of an elegant physics experiment.

Millikan managed to isolate several charged droplets of water in space between the plates of a capacitor. 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 between the plates was turned on, the droplet slowly moved upward under the influence of electrical attraction. When the field was turned off, it fell under the influence of gravity. By 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 convincing evidence that electrons were particles with the same charge and mass. By 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, he 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 consist 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 there was clearly a lack of experimental data that would make it possible to make a choice in favor of one or another model.

Most physicists accepted J.J. Thomson's model: an atom as a uniformly charged positive ball with a diameter of approximately 10-8 cm with negative electrons floating inside. In 1909, Ernst Rutherford (assisted by Hans Geiger and Ernst Marsden) conducted an experiment to understand the actual structure of the atom. In this experiment, heavy positively charged alpha particles moving at a speed of 20 km/s passed through thin gold foil and were scattered on gold atoms, deviating from the original direction of motion. To determine the degree of deviation, Geiger and Marsden had to use a microscope to observe the flashes on the scintillator plate that occurred where the alpha particle hit the plate. Over the course of two years, about a million flares were counted and it was proven that approximately one particle in 8000, as a result of scattering, changes its direction of motion by more than 90° (that is, turns back). This could not possibly happen in Thomson’s “loose” atom. The results clearly supported the so-called planetary model of the atom - a massive tiny nucleus measuring about 10-13 cm and electrons rotating around this nucleus at a distance of about 10-8 cm.