Winter will begin soon, and with it the long-awaited time. In the meantime, we invite you to keep your child busy with equally exciting experiments at home, because you want miracles not only for the New Year, but every day.

In this article we will talk about experiments that clearly demonstrate to children such physical phenomena as: atmospheric pressure, properties of gases, the movement of air currents and from various objects.

These will cause surprise and delight in your child, and even a four-year-old can repeat them under your supervision.

How to fill a water bottle without hands?

We will need:

• a bowl of cold water, colored for clarity;
• hot water;
• Glass bottle.

Pour hot water into the bottle several times so that it warms up well. Turn the empty hot bottle upside down and place it in a bowl of cold water. We observe how water is drawn from a bowl into a bottle and, contrary to the law of communicating vessels, the water level in the bottle is much higher than in the bowl.

Why is this happening? Initially, a well-warmed bottle is filled with warm air. As the gas cools, it contracts, filling a smaller and smaller volume. Thus, a low-pressure environment is formed in the bottle, where water is directed to restore balance, because atmospheric pressure presses on the water from the outside. Colored water will flow into the bottle until the pressure inside and outside the glass vessel is equalized.

Dancing coin

For this experiment we will need:

• a glass bottle with a narrow neck that can be completely blocked by a coin;
• coin;
• water;
• freezer.

Leave the empty, open glass bottle in the freezer (or outside in winter) for 1 hour. We take out the bottle, moisten the coin with water and place it on the neck of the bottle. After a few seconds, the coin will begin to jump on the neck and make characteristic clicks.

This behavior of the coin is explained by the ability of gases to expand when heated. Air is a mixture of gases, and when we took the bottle out of the refrigerator it was filled with cold air. At room temperature, the gas inside began to heat up and increase in volume, while the coin blocked its exit. So the warm air began to push out the coin, and in due time it began to bounce on the bottle and click.

It is important that the coin is wet and fits tightly to the neck, otherwise the trick will not work and warm air will freely leave the bottle without tossing a coin.

Glass - sippy cup

Invite your child to turn a glass filled with water over so that the water does not spill out of it. Surely the baby will refuse such a scam or will pour water into the basin at the first attempt. Teach him the next trick. We will need:

• glass of water;
• a piece of cardboard;
• basin/sink for safety net.

We cover the glass of water with cardboard, and holding the latter with our hand, we turn the glass over, after which we remove our hand. It is better to carry out this experiment over a basin/sink, because... If you keep the glass upside down for a long time, the cardboard will eventually get wet and water will spill. It is better not to use paper instead of cardboard for the same reason.

Discuss with your child: why does the cardboard prevent water from flowing out of the glass, since it is not glued to the glass, and why does the cardboard not immediately fall under the influence of gravity?

Do you want to play with your child easily and with pleasure?

When wet, cardboard molecules interact with water molecules, attracting each other. From this moment on, water and cardboard interact as one. In addition, wet cardboard prevents air from entering the glass, which prevents the pressure inside the glass from changing.

At the same time, not only the water from the glass presses on the cardboard, but also the air from outside, which forms the force of atmospheric pressure. It is atmospheric pressure that presses the cardboard to the glass, forming a kind of lid, and prevents water from spilling out.

Experiment with a hairdryer and a strip of paper

We continue to surprise the child. We build a structure from books and attach a strip of paper to them on top (we did this with tape). Paper hangs from the books as shown in the photo. You choose the width and length of the strip based on the power of the hair dryer (we took 4 by 25 cm).

Now turn on the hair dryer and direct the air stream parallel to the lying paper. Despite the fact that the air does not blow on the paper, but next to it, the strip rises from the table and develops as if in the wind.

Why does this happen and what makes the strip move? Initially, the strip is acted upon by gravity and pressed by atmospheric pressure. The hairdryer creates a strong air flow along the paper. In this place, a zone of low pressure is formed towards which the paper is deflected.

Shall we blow out the candle?

We begin to teach the baby to blow before he is one year old, preparing him for his first birthday. When the child has grown up and has fully mastered this skill, offer it to him through a funnel. In the first case, positioning the funnel so that its center corresponds to the level of the flame. And the second time, so that the flame is along the edge of the funnel.

Surely the child will be surprised that all his efforts in the first case will not give the desired result in the form of an extinguished candle. In the second case, the effect will be immediate.

Why? When air enters the funnel, it is evenly distributed along its walls, so the maximum flow rate is observed at the edge of the funnel. And in the center the air speed is low, which prevents the candle from going out.

Shadow from a candle and from a fire

We will need:

• candle;
• flashlight.

We light the fire and place it near a wall or other screen and illuminate it with a flashlight. A shadow from the candle itself will appear on the wall, but there will be no shadow from the fire. Ask your child why this happened?

The thing is that fire itself is a source of light and transmits other light rays through itself. And since a shadow appears when an object is illuminated from the side and does not transmit rays of light, fire cannot produce a shadow. But it's not that simple. Depending on the substance being burned, the fire can be filled with various impurities, soot, etc. In this case, you can see a blurry shadow, which is precisely what these inclusions provide.

Did you like the selection of experiments to do at home? Share with your friends by clicking on the social network buttons, so that other mothers can please their kids with interesting experiments!

1. Theory and methods of teaching physics at school. General issues. Ed. S.E. Kamenetsky, N.S. Purysheva. M.: Publishing center "Academy", 2000.

2. Experiments and observations in physics homework. S.F. Pokrovsky. Moscow, 1963.

3. Perelman Ya.I. collection of entertaining books (29 pcs.). Quantum. Year of publication: 1919-2011.

“Tell me and I’ll forget, show me and I’ll remember, let me try and I’ll learn.”

Ancient Chinese proverb

One of the main components of providing an information and educational environment for the subject of physics is educational resources and the proper organization of educational activities. A modern student who can easily navigate the Internet can use various educational resources: http://sites.google.com/site/physics239/poleznye-ssylki/sajty, http://www.fizika.ru, http://www .alleng.ru/edu/phys, http://www.int-edu.ru/index.php, http://class-fizika.narod.ru, http://www.globallab.ru, http:/ /barsic.spbu.ru/www/edu/edunet.html, http://www.374.ru/index.php?x=2007-11-13-14, etc. Today, the main task of a teacher is to teach students to learn, to strengthen their ability for self-development in the process of education in the modern information environment.

Students' learning of physical laws and phenomena should always be reinforced by practical experimentation. To do this, you need appropriate equipment, which is available in the physics classroom. The use of modern technology in the educational process makes it possible to replace a visual practical experiment with a computer model. The website http://www.youtube.com (search for “physics experiments”) contains experiments conducted in real conditions.

An alternative to using the Internet can be an independent educational experiment that a student can conduct outside of school: on the street or at home. It is clear that experiments given at home should not use complex educational equipment, as well as investments in material costs. These can be experiments with air, water, and with various objects that are accessible to the child. Of course, the scientific nature and value of such experiments is minimal. But if a child himself can verify a law or phenomenon discovered many years before, this is simply invaluable for the development of his practical skills. An experiment is a creative task and having done something on his own, the student, whether he wants it or not, will think about how easier it is to carry out the experiment, where he has encountered a similar phenomenon in practice, where else this phenomenon may be useful.

What does a child need to conduct the experiment at home? First of all, this is a fairly detailed description of the experience, indicating the necessary items, where it is said in a form accessible to the student what needs to be done and what to pay attention to. In school physics textbooks at home, it is suggested that you either solve problems or answer questions posed at the end of the paragraph. There you can rarely find a description of an experience that is recommended for schoolchildren to conduct independently at home. Therefore, if a teacher asks students to do something at home, then he is obliged to give them detailed instructions.

For the first time, home experiments and observations in physics began to be carried out in the 1934/35 academic year by S.F. Pokrovsky. at school No. 85 in the Krasnopresnensky district of Moscow. Of course, this date is conditional; even in ancient times, teachers (philosophers) could advise their students to observe natural phenomena, test any law or hypothesis in practice at home. In his book S.F. Pokrovsky showed that home experiments and observations in physics conducted by the students themselves: 1) enable our school to expand the area of ​​connection between theory and practice; 2) develop students’ interest in physics and technology; 3) awaken creative thought and develop the ability to invent; 4) accustom students to independent research work; 5) develop valuable qualities in them: observation, attention, perseverance and accuracy; 6) supplement classroom laboratory work with material that cannot be done in class (a series of long-term observations, observation of natural phenomena, etc.); 7) accustom students to conscious, purposeful work.

In the textbooks “Physics-7”, “Physics-8” (authors A.V. Peryshkin), after studying individual topics, students are offered experimental observation tasks that can be performed at home, explain their results, and write a short report on the work.

Since one of the requirements for home experiment is simplicity in implementation, therefore, it is advisable to use them at the initial stage of teaching physics, when children’s natural curiosity has not yet died out. It is difficult to come up with experiments to conduct at home on topics such as, for example: most of the topics “Electrodynamics” (except for electrostatics and simple electrical circuits), “Atomic Physics”, “Quantum Physics”. On the Internet you can find a description of home experiments: http://adalin.mospsy.ru/l_01_00/op13.shtml, http://ponomari-school.ucoz.ru/index/0-52, http://ponomari-school .ucoz.ru/index/0-53, http://elkin52.narod.ru/opit/opit.htm, http://festival. 1september.ru/ articles/599512, etc. I have prepared a selection of home experiments with brief instructions for implementation.

Home experiments in physics represent an educational activity for students, which allows not only to solve the teacher’s educational and methodological tasks, but also allows the student to see that physics is not only a subject of the school curriculum. The knowledge gained in the lesson is something that can actually be used in life, both from a practical point of view, and for assessing some parameters of bodies or phenomena, and for predicting the consequences of any actions. Well, is 1 dm3 a lot or a little? Most students (and adults too) find it difficult to answer this question. But you just have to remember that a regular carton of milk has a volume of 1 dm3, and it immediately becomes easier to estimate the volumes of bodies: after all, 1 m3 is a thousand of these bags! It is from such simple examples that understanding of physical quantities comes. When performing laboratory work, students practice computational skills and become convinced from their own experience of the validity of the laws of nature. No wonder Galileo Galilei argued that science is true when it becomes understandable even to the uninitiated. So home experiments are an extension of the information and educational environment of the modern schoolchild. After all, life experience, acquired over the years by trial and error, is nothing more than elementary knowledge of physics.

The simplest measurements.

Exercise 1.

Having learned to use a ruler and tape measure or a tape measure in class, use these devices to measure the lengths of the following objects and distances:

a) the length of the index finger; b) elbow length, i.e. the distance from the end of the elbow to the end of the middle finger; c) the length of the foot from the end of the heel to the end of the big toe; d) neck circumference, head circumference; e) the length of a pen or pencil, a match, a needle, the length and width of a notebook.

Write down the obtained data in your notebook.

Task 2.

Measure your height:

1. In the evening, before going to bed, take off your shoes, stand with your back to the door frame and lean tightly. Keep your head straight. Have someone use a square to make a small pencil mark on the jamb. Measure the distance from the floor to the marked line with a tape measure or centimeter. Express the measurement result in centimeters and millimeters, write it down in a notebook indicating the date (year, month, day, hour).

2. Do the same in the morning. Record the result again and compare the results of the evening and morning measurements. Bring the recording to class.

Task 3.

Measure the thickness of a sheet of paper.

Take a book a little more than 1cm thick and, opening the top and bottom covers of the binding, apply a ruler to the stack of paper. Select a stack 1 cm thick = 10 mm = 10,000 microns. Divide 10,000 microns by the number of sheets to express the thickness of one sheet in microns. Write the result in your notebook. Think about how you can increase the measurement accuracy?

Task 4.

Determine the volume of a matchbox, rectangular eraser, juice or milk carton. Measure the length, width and height of the matchbox in millimeters. Multiply the resulting numbers, i.e. find the volume. Express the result in cubic millimeters and cubic decimeters (liters), write it down. Take measurements and calculate the volumes of the other proposed bodies.

Task 5.

Take a watch with a second hand (you can use an electronic watch or a stopwatch) and, looking at the second hand, watch its movement for one minute (on an electronic watch, watch the digital values). Next, ask someone to note out loud the beginning and end of a minute on the clock, while you close your eyes at this time, and with your eyes closed, perceive the duration of one minute. Do the opposite: standing with your eyes closed, try to set the duration to one minute. Have another person monitor you by the clock.

Task 6.

Learn to quickly find your pulse, then take a second hand watch or electronic watch and find out how many pulse beats you see in one minute. Then do the reverse: counting the pulse beats, set the duration to one minute (assign another person to monitor the clock)

Note. The great scientist Galileo, observing the swinging of the chandelier in the Florence Cathedral and using (instead of a clock) the beat of his own pulse, established the first law of pendulum oscillation, which formed the basis of the doctrine of oscillatory motion.

Task 7.

Using a stopwatch, determine as accurately as possible how many seconds it takes you to run a distance of 60 (100) m. Divide the distance by time, i.e. Determine the average speed in meters per second. Convert meters per second to kilometers per hour. Write down the results in your notebook.

Pressure.

Exercise 1.

Determine the pressure produced by the stool. Place a piece of squared paper under the leg of the chair, circle the leg with a sharpened pencil and, taking out the paper, count the number of square centimeters. Calculate the area of ​​support of the four legs of the chair. Think about how else you can calculate the area of ​​support of the legs?

Find out your weight along with your stool. This can be done using scales designed for weighing people. To do this, you need to pick up a chair and stand on the scales, i.e. weigh yourself and the chair.

If you cannot find out the mass of the stool you have for some reason, take the mass of the stool equal to 7 kg (the average mass of chairs). Add the average weight of stool to your own body weight.

Calculate your weight along with the chair. To do this, the sum of the masses of the chair and the person must be multiplied by approximately ten (more precisely, by 9.81 m/s2). If the mass was in kilograms, then you will get the weight in newtons. Using the formula p = F/S, calculate the pressure of the chair on the floor if you are sitting on a chair without your feet touching the floor. Write down all measurements and calculations in your notebook and bring them to class.

Task 2.

Pour water into the glass all the way to the rim. Cover the glass with a piece of thick paper and, holding the paper with your palm, quickly turn the glass upside down. Now remove your palm. Water will not spill out of the glass. The atmospheric air pressure on the piece of paper is greater than the water pressure on it.

Just in case, do all this over the basin, because if the paper is slightly skewed and if you are still insufficiently experienced at first, the water may spill.

Task 3.

A “diving bell” is a large metal cap, which is lowered with the open side to the bottom of a reservoir to carry out any work. After lowering it into the water, the air contained in the cap is compressed and does not let water inside this device. Only a little water remains at the very bottom. In such a bell, people can move and do the work assigned to them. Let's make a model of this device.

Take a glass and a plate. Pour water into a plate and place a glass turned upside down in it. The air in the glass will compress, and the bottom of the plate under the glass will be very slightly filled with water. Place a stopper on the water before placing the glass in the plate. It will show how little water is left at the bottom.

Task 4.

This entertaining experience is about three hundred years old. It is attributed to the French scientist René Descartes (his last name is Cartesius in Latin). The experiment was so popular that the Cartesian Diver toy was created based on it. You and I can do this experiment. To do this you will need a plastic bottle with a stopper, a pipette and water. Fill the bottle with water, leaving two to three millimeters to the edge of the neck. Take a pipette, fill it with some water and drop it into the neck of the bottle. Its upper rubber end should be at or slightly above the water level in the bottle. In this case, you need to ensure that with a slight push with your finger the pipette sinks, and then slowly floats up on its own. Now close the cap and squeeze the sides of the bottle. The pipette will go to the bottom of the bottle. Release the pressure on the bottle and it will float again. The fact is that we slightly compressed the air in the neck of the bottle and this pressure was transferred to the water. Water entered the pipette - it became heavier and sank. When the pressure was released, the compressed air inside the pipette removed excess water, our “diver” became lighter and surfaced. If at the beginning of the experiment the “diver” does not listen to you, then you need to adjust the amount of water in the pipette.

When the pipette is at the bottom of the bottle, it is easy to see how, as the pressure on the walls of the bottle increases, water enters the pipette, and when the pressure is released, it comes out of it.

Task 5.

Make a fountain, known in the history of physics as Heron's fountain. Pass a piece of glass tube with the end pulled out through a cork inserted into a thick-walled bottle. Fill the bottle with enough water to keep the end of the tube submerged. Now, in two or three steps, blow air into the bottle with your mouth, squeezing the end of the tube after each blow. Release your finger and watch the fountain.

If you want to get a very strong fountain, then use a bicycle pump to pump air. However, remember that with more than one or two strokes of the pump, the cork may fly out of the bottle and you will need to hold it with your finger, and with a very large number of strokes, the compressed air can rupture the bottle, so you need to use the pump very carefully.

Archimedes' law.

Exercise 1.

Prepare a wooden stick (twig), a wide jar, a bucket of water, a wide bottle with a stopper and a rubber thread at least 25 cm long.

1. Push the stick into the water and watch it push out of the water. Do this several times.

2. Push the jar bottom down into the water and watch how it is pushed out of the water. Do this several times. Remember how difficult it is to push a bucket bottom down into a barrel of water (if you haven’t observed this, do it at any opportunity).

3. Fill the bottle with water, cap it and tie a rubber thread to it. Holding the thread by the free end, watch how it shortens as the bubble is immersed in water. Do this several times.

4. A tin plate sinks in water. Fold the edges of the plate to form a box. Place it on the water. She swims. Instead of a tin plate, you can use a piece of foil, preferably hard. Make a box out of foil and place it on the water. If the box (made of foil or metal) does not leak, it will float on the surface of the water. If the box takes on water and sinks, think about how to fold it so that water does not get inside.

Describe and explain these phenomena in your notebook.

Task 2.

Take a piece of shoe polish or wax the size of an ordinary hazelnut, make a regular ball out of it and, using a small load (insert a piece of wire), make it sink smoothly in a glass or test tube with water. If the ball sinks without a load, then, of course, it should not be loaded. If there is no pitch or wax, you can cut a small ball from the pulp of a raw potato.

Add a little saturated solution of pure table salt to the water and stir lightly. First ensure that the ball is kept in balance in the middle of the glass or test tube, and then that it floats to the surface of the water.

Note. The proposed experiment is a variant of the well-known experiment with a chicken egg and has a number of advantages over the latter experiment (it does not require the presence of a freshly laid chicken egg, the presence of a large high vessel and a large amount of salt).

Task 3.

Take a rubber ball, a table tennis ball, pieces of oak, birch and pine wood and let them float on the water (in a bucket or basin). Carefully observe the swimming of these bodies and determine by eye which part of these bodies is immersed in water when swimming. Remember how deep a boat, log, ice floe, ship, etc. sinks into the water.

Surface tension forces.

Exercise 1.

Prepare a glass plate for this experiment. Wash it well with soap and warm water. When dry, wipe one side with a cotton swab dipped in cologne. Do not touch its surface with anything, and now you only need to take the plate by the edges.

Take a piece of smooth white paper and drip stearin from a candle onto it so that you get an even, flat stearin plate the size of the bottom of a glass.

Place the stearic and glass plates side by side. Drop a small drop of water from the pipette onto each of them. On a stearine plate you will get a hemisphere with a diameter of about 3 millimeters, and on a glass plate the drop will spread. Now take the glass plate and tilt it. The drop has already spread, and now it will flow further. Water molecules are more readily attracted to glass than to each other. Another drop will roll on the stearin when the plate is tilted in different directions. Water cannot adhere to stearin; it does not wet it; water molecules are attracted to each other more strongly than to stearin molecules.

Note. In the experiment, carbon black can be used instead of stearin. You need to drop water from a pipette onto the smoked surface of the metal plate. The drop will turn into a ball and quickly roll along the soot. To prevent the next drops from immediately rolling off the plate, you need to keep it strictly horizontal.

Task 2.

The blade of a safety razor, despite the fact that it is steel, can float on the surface of the water. You just need to make sure that it does not get wet with water. To do this, you need to lightly grease it. Place the blade carefully on the surface of the water. Place a needle across the blade, and one button at each end of the blade. The load will be quite solid, and you can even see how the razor was pressed into the water. It seems as if there is an elastic film on the surface of the water, which holds such a load.

You can also make a needle float by first lubricating it with a thin layer of fat. It must be placed on water very carefully so as not to puncture the surface layer of water. This may not work right away; it will take some patience and practice.

Pay attention to how the needle is positioned on the water. If the needle is magnetized, then it is a floating compass! And if you take a magnet, you can make the needle travel through water.

Task 3.

Place two identical pieces of cork on the surface of clean water. Use the ends of a match to bring them together. Please note: as soon as the distance between the plugs decreases to half a centimeter, this water gap between the plugs will itself shrink, and the plugs will quickly attract each other. But it’s not just traffic jams that tend towards each other. They are well attracted to the edge of the container in which they float. To do this, you just need to bring them a short distance closer to it.

Try to explain the phenomenon you saw.

Task 4.

Take two glasses. Fill one of them with water and place it higher. Place another glass, empty, below. Dip the end of a strip of clean cloth into a glass of water, and its other end into the lower glass. The water, taking advantage of the narrow spaces between the fibers of the matter, will begin to rise, and then, under the influence of gravity, will flow into the lower glass. So a strip of matter can be used as a pump.

Task 5.

This experiment (Plateau's experiment) clearly shows how, under the influence of surface tension forces, a liquid turns into a ball. For this experiment, alcohol and water are mixed in such a ratio that the mixture has the density of oil. Pour this mixture into a glass vessel and add vegetable oil to it. The oil is immediately located in the middle of the vessel, forming a beautiful, transparent, yellow ball. Conditions have been created for the ball as if it were in zero gravity.

To do the Plateau experiment in miniature, you need to take a very small transparent vial. It should contain a little sunflower oil - about two tablespoons. The fact is that after the experiment the oil will become completely unsuitable for consumption, and the products must be protected.

Pour some sunflower oil into the prepared bottle. Use a thimble as a utensil. Drop a few drops of water and the same amount of cologne into it. Stir the mixture, put it in a pipette and release one drop into the oil. If the drop, having become a ball, goes to the bottom, it means that the mixture is heavier than oil, it needs to be lightened. To do this, add one or two drops of cologne to the thimble. Cologne is made from alcohol and is lighter than water and oil. If the ball from the new mixture begins not to fall, but, on the contrary, to rise, it means that the mixture has become lighter than oil and you need to add a drop of water to it. So, by alternating adding water and cologne in small, dropwise doses, you can ensure that a ball of water and cologne will “hang” in the oil at any level. The classic Plateau experiment in our case looks the other way around: oil and a mixture of alcohol and water have swapped places.

Note. The experiment can be assigned at home and while studying the topic “Archimedes’ Law”.

Task 6.

How to change the surface tension of water? Pour clean water into two plates. Take scissors and cut two narrow strips, one square wide, from a sheet of checkered paper. Take one strip and, holding it over one plate, cut pieces from the strip one square at a time, trying to do this so that the pieces falling into the water are located on the water in a ring in the middle of the plate and do not touch each other or the edges of the plate.

Take a piece of soap with a pointed end and touch the pointed end to the surface of the water in the middle of the ring of papers. What are you observing? Why do pieces of paper start to scatter?

Now take another strip, also cut off several pieces of paper from it over another plate and, touching a piece of sugar to the middle of the surface of the water inside the ring, keep it in the water for some time. The pieces of paper will move closer to each other as they gather.

Answer the question: how did the surface tension of water change due to the admixture of soap and the admixture of sugar?

Exercise 1.

Take a long, heavy book, tie it with a thin thread and attach a 20 cm long rubber thread to the thread.

Place the book on the table and very slowly begin to pull on the end of the rubber thread. Try to measure the length of the stretched rubber thread as the book begins to slide.

Measure the length of the stretched book while moving the book evenly.

Place two thin cylindrical pens (or two cylindrical pencils) under the book and pull the end of the thread in the same way. Measure the length of the stretched thread when the book moves evenly on the rollers.

Compare the three results obtained and draw conclusions.

Note. The next task is a variation of the previous one. It is also aimed at comparing static friction, sliding friction and rolling friction.

Task 2.

Place a hexagonal pencil on the book parallel to its spine. Slowly lift the top edge of the book until the pencil begins to slide down. Slightly reduce the tilt of the book and secure it in this position by placing something under it. Now the pencil, if you put it on the book again, will not move. It is held in place by a frictional force - the static friction force. But if this force is slightly weakened - and for this it is enough to click your finger on the book - and the pencil will creep down until it falls on the table. (The same experiment can be done, for example, with a pencil case, matchbox, eraser, etc.)

Think about why it is easier to pull a nail out of a board if you rotate it around its axis?

To move a thick book on the table with one finger, you need to apply some force. And if you put two round pencils or pens under the book, which in this case will be roller bearings, the book will easily move with a weak push with your little finger.

Carry out experiments and compare the static friction force, the sliding friction force and the rolling friction force.

Task 3.

In this experiment, two phenomena can be observed at once: inertia, experiments with which will be described further, and friction.

Take two eggs: one raw and the other hard-boiled. Place both eggs on a large plate. You can see that a boiled egg behaves differently than a raw egg: it spins much faster.

In a boiled egg, the white and yolk are rigidly connected to their shell and to each other because are in a solid state. And when we unscrew a raw egg, we first untwist only the shell, only then, due to friction, layer by layer the rotation is transferred to the white and yolk. Thus, the liquid white and yolk, by their friction between the layers, slow down the rotation of the shell.

Note. Instead of raw and boiled eggs, you can tighten two pans, one of which contains water, and the other contains the same amount of cereal.

Center of gravity.

Exercise 1.

Take two faceted pencils and hold them parallel in front of you, placing a ruler on them. Start bringing the pencils closer together. The rapprochement will occur in alternating movements: first one pencil moves, then the other. Even if you want to interfere with their movement, you will not succeed. They will still move in turns.

As soon as the pressure on one pencil increases and the friction increases so much that the pencil cannot move further, it stops. But the second pencil can now move under the ruler. But after a while the pressure above it becomes greater than above the first pencil, and due to increased friction it stops. Now the first pencil can move. So, moving one by one, the pencils will meet in the very middle of the ruler at its center of gravity. This can be easily seen from the divisions of the ruler.

This experiment can also be done with a stick, holding it on outstretched fingers. As you move your fingers, you will notice that they, also moving alternately, will meet under the very middle of the stick. True, this is only a special case. Try doing the same with a regular floor brush, shovel or rake. You will see that the fingers do not meet in the middle of the stick. Try to explain why this happens.

Task 2.

This is an old, very visual experience. You probably have a penknife (folding knife) and a pencil too. Sharpen the pencil so that it has a sharp end, and stick a half-open pocket knife a little above the end. Place the tip of the pencil on your index finger. Find a position of the half-open knife on the pencil in which the pencil will stand on your finger, swaying slightly.

Now the question is: where is the center of gravity of a pencil and a pocket knife?

Task 3.

Determine the position of the center of gravity of a match with and without a head.

Place a matchbox on the table on its long narrow edge and place a match without a head on the box. This match will serve as a support for another match. Take a match with its head and balance it on the support so that it lies horizontally. Use a pen to mark the position of the center of gravity of the match with the head.

Scrape the head off the match and place the match on the support so that the ink dot you marked rests on the support. Now you will not be able to do this: the match will not lie horizontally, since the center of gravity of the match has moved. Determine the position of the new center of gravity and notice which way it has moved. Mark with a pen the center of gravity of the match without the head.

Bring a match with two points to class.

Task 4.

Determine the position of the center of gravity of the flat figure.

Cut out a figure of any arbitrary (any bizarre) shape from cardboard and punch several holes in different random places (it is better if they are located closer to the edges of the figure, this will increase accuracy). Drive a small headless nail or needle into a vertical wall or counter and hang a figure on it through any hole. Please note: the figure should swing freely on the nail.

Take a plumb line, consisting of a thin thread and a weight, and throw its thread over a nail so that it points in the vertical direction to a non-suspended figure. Mark the vertical direction of the thread on the figure with a pencil.

Remove the figure, hang it by any other hole and again, using a plumb line and a pencil, mark the vertical direction of the thread on it.

The intersection point of the vertical lines will indicate the position of the center of gravity of this figure.

Pass a thread with a knot at the end through the center of gravity you have found, and hang the figure on this thread. The figure should be held almost horizontally. The more accurately the experiment is done, the more horizontal the figure will remain.

Task 5.

Determine the center of gravity of the hoop.

Take a small hoop (for example, a hoop) or make a ring from a flexible rod, from a narrow strip of plywood or stiff cardboard. Hang it on a nail and lower the plumb line from the hanging point. When the plumb line has calmed down, mark on the hoop the points where it touches the hoop and between these points, pull and secure a piece of thin wire or fishing line (you need to pull it tightly enough, but not so much that the hoop changes its shape).

Hang the hoop on a nail at any other point and do the same. The point of intersection of the wires or lines will be the center of gravity of the hoop.

Note: the center of gravity of the hoop lies outside the substance of the body.

Tie a thread to the intersection of the wires or fishing lines and hang a hoop on it. The hoop will be in indifferent equilibrium, since the center of gravity of the hoop and the point of its support (suspension) coincide.

Task 6.

You know that the stability of the body depends on the position of the center of gravity and the size of the support area: the lower the center of gravity and the larger the support area, the more stable the body.

Keeping this in mind, take a block or an empty matchbox and, placing it alternately on the squared paper on the widest, middle and smallest edges, trace it each time with a pencil to get three different areas of support. Calculate the dimensions of each area in square centimeters and mark them on paper.

Measure and record the height of the center of gravity of the box for all three cases (the center of gravity of the matchbox lies at the intersection of the diagonals). Conclude which position of the boxes is most stable.

Task 7.

Sit on a chair. Place your legs vertically without putting them under the seat. Sit completely straight. Try standing up without bending forward, extending your arms forward, or moving your legs under the seat. You won't succeed - you won't be able to get up. Your center of gravity, which is somewhere in the middle of your body, will prevent you from standing up.

What condition must be met in order to stand up? You need to lean forward or tuck your legs under the seat. When we get up, we always do both. In this case, the vertical line passing through your center of gravity must necessarily pass through at least one of the feet of your legs or between them. Then the balance of your body will be quite stable, you can easily stand up.

Well, now try to stand up, holding dumbbells or an iron in your hands. Extend your arms forward. You may be able to stand up without bending over or bending your legs underneath you.

Exercise 1.

Place a postcard on the glass, and place a coin or checker on the postcard so that the coin is above the glass. Click on the card. The card should fly out and the coin (checker) should fall into the glass.

Task 2.

Place a double sheet of notebook paper on the table. Place a stack of books at least 25cm high on one half of the sheet.

Slightly lifting the second half of the sheet above the table level with both hands, quickly pull the sheet towards you. The sheet should come free from under the books, but the books should remain in place.

Place the book on the sheet of paper again and pull it now very slowly. The books will move with the sheet.

Task 3.

Take a hammer, tie a thin thread to it, but so that it can withstand the weight of the hammer. If one thread doesn't hold up, take two threads. Slowly lift the hammer up by the thread. The hammer will hang on a thread. And if you want to lift it again, but not slowly, but with a quick jerk, the thread will break (make sure that the hammer, when falling, does not break anything underneath it). The inertia of the hammer is so great that the thread could not stand it. The hammer did not have time to quickly follow your hand, it remained in place, and the thread broke.

Task 4.

Take a small ball made of wood, plastic or glass. Make a groove out of thick paper and place the ball in it. Move the groove quickly across the table and then suddenly stop it. The ball will continue to move by inertia and roll, jumping out of the groove. Check where the ball will roll if:

a) pull the chute very quickly and stop it abruptly;

b) pull the chute slowly and stop suddenly.

Task 5.

Cut the apple in half, but not all the way, and leave it hanging on the knife.

Now hit something hard, such as a hammer, with the blunt side of the knife with the apple hanging on top of it. The apple, continuing to move by inertia, will be cut and split into two halves.

Exactly the same thing happens when chopping wood: if it is not possible to split a block of wood, they usually turn it over and hit it as hard as they can with the butt of the ax on a solid support. The block of wood, continuing to move by inertia, is impaled deeper on the ax and splits in two.

Exercise 1.

Place a wooden board and a mirror on the table nearby. Place a room thermometer between them. After some fairly long time, we can assume that the temperatures of the wooden board and the mirror are equal. The thermometer shows the air temperature. The same as, obviously, the board and the mirror.

Touch your palm to the mirror. You will feel the coldness of the glass. Immediately touch the board. It will seem much warmer. What's the matter? After all, the temperature of the air, the board and the mirror are the same.

Why did the glass seem colder than wood? Try to answer this question.

Glass is a good conductor of heat. As a good conductor of heat, glass will immediately begin to heat up from your hand and will begin to greedily “pump” heat out of it. This is why you feel cold in your palm. Wood conducts heat worse. It will also begin to “pump” heat into itself, heating up from your hand, but it does this much more slowly, so you do not feel the sharp cold. So wood seems warmer than glass, although both have the same temperature.

Note. Instead of wood, you can use foam.

Task 2.

Take two identical smooth glasses, pour boiling water into one glass up to 3/4 of its height and immediately cover the glass with a piece of porous (not laminated) cardboard. Place a dry glass upside down on the cardboard and watch how its walls gradually fog up. This experiment confirms the properties of vapors to diffuse through partitions.

Task 3.

Take a glass bottle and cool it well (for example, by putting it in the cold or putting it in the refrigerator). Pour water into a glass, mark the time in seconds, take a cold bottle and, holding it in both hands, lower your throat into the water.

Count how many air bubbles come out of the bottle during the first minute, during the second and during the third minute.

Record your results. Bring your work report to class.

Task 4.

Take a glass bottle, warm it well over water vapor and pour boiling water into it to the very top. Place the bottle on the windowsill and mark the time. After 1 hour, mark the new water level in the bottle.

Bring your work report to class.

Task 5.

Establish the dependence of the rate of evaporation on the free surface area of ​​the liquid.

Fill a test tube (small bottle or vial) with water and pour it onto a tray or flat plate. Fill the same container with water again and place it next to the plate in a quiet place (for example, on a cabinet), allowing the water to evaporate quietly. Record the start date of the experiment.

Once the water on the plate has evaporated, mark and record the time again. See how much water has evaporated from the test tube (bottle).

Draw a conclusion.

Task 6.

Take a tea glass, fill it with pieces of clean ice (for example, from a crushed icicle) and bring the glass into the room. Pour room water into a glass to the brim. When all the ice has melted, see how the water level in the glass has changed. Draw a conclusion about the change in the volume of ice during melting and about the density of ice and water.

Task 7.

Watch the snow sublimate. On a frosty day in winter, take half a glass of dry snow and place it outside the house under some kind of canopy so that snow does not get into the glass from the air.

Record the start date of the experiment and observe the snow sublimation. Once all the snow has cleared, write down the date again.

Write a report.

Topic: “Determination of the average speed of a person.”

Purpose: using the speed formula, determine the speed of a person’s movement.

Equipment: mobile phone, ruler.

Progress:

1. Use a ruler to determine the length of your step.

2. Walk throughout the apartment, counting the number of steps.

3. Using a mobile phone stopwatch, determine the time of your movement.

4. Using the speed formula, determine the speed of movement (all quantities must be expressed in the SI system).

Topic: “Determination of milk density.”

Purpose: check the quality of the product by comparing the value of the tabulated density of the substance with the experimental one.

Progress:

1. Measure the mass of the milk package using a check scale in the store (there should be a marking slip on the package).

2. Using a ruler, determine the dimensions of the package: length, width, height, - convert the measurement data into the SI system and calculate the volume of the package.

4. Compare the obtained data with the table density value.

5. Draw a conclusion about the results of the work.

Topic: “Determination of the weight of a package of milk.”

Goal: using the table density of a substance, calculate the weight of a package of milk.

Equipment: milk carton, substance density table, ruler.

Progress:

1. Using a ruler, determine the dimensions of the package: length, width, height, - convert the measurement data into the SI system and calculate the volume of the package.

2. Using the table density of milk, determine the mass of the package.

3. Using the formula, determine the weight of the package.

4. Graphically depict the linear dimensions of the package and its weight (two drawings).

5. Draw a conclusion about the results of the work.

Topic: “Determination of the pressure exerted by a person on the floor”

Purpose: using the formula, determine the pressure of a person on the floor.

Equipment: bathroom scales, checkered notebook paper.

Progress:

1. Stand on a notebook sheet and trace your foot.

2. To determine the area of ​​your foot, count the number of complete cells and, separately, incomplete cells. Reduce the number of incomplete cells by half, add the number of complete cells to the result obtained, and divide the sum by four. This is the area of ​​one foot.

3. Using a bathroom scale, determine your body weight.

4. Using the solid body pressure formula, determine the pressure exerted on the floor (all values ​​must be expressed in SI units). Don't forget that a person stands on two legs!

5. Draw a conclusion about the results of the work. Attach a sheet with the outline of the foot to your work.

Topic: “Checking the phenomenon of hydrostatic paradox.”

Purpose: using the general pressure formula, determine the pressure of the liquid at the bottom of the vessel.

Equipment: measuring vessel, high-walled glass, vase, ruler.

Progress:

1. Use a ruler to determine the height of the liquid poured into the glass and vase; it should be the same.

2. Determine the mass of liquid in the glass and vase; To do this, use a measuring vessel.

3. Determine the area of ​​the bottom of the glass and vase; To do this, measure the diameter of the bottom with a ruler and use the formula for the area of ​​a circle.

4. Using the general pressure formula, determine the water pressure at the bottom of the glass and vase (all values ​​must be expressed in the SI system).

5. Illustrate the course of the experiment with a drawing.

Topic: “Determination of the density of the human body.”

Purpose: using Archimedes' law and the formula for calculating density, determine the density of the human body.

Equipment: liter jar, floor scales.

Progress:

4. Using a bathroom scale, determine your mass.

5. Using the formula, determine the density of your body.

6. Draw a conclusion about the results of the work.

Topic: “Definition of Archimedean force.”

Purpose: using Archimedes' law, determine the buoyant force acting on the human body from the liquid.

Equipment: liter jar, bath.

Progress:

1. Fill the bathtub with water and mark the water level along the edge.

2. Immerse yourself in the bath. The liquid level will increase. Make a mark along the edge.

3. Using a liter jar, determine your volume: it is equal to the difference in the volumes marked along the edge of the bath. Convert the result to the SI system.

5. Illustrate the experiment performed by indicating the Archimedes force vector.

6. Draw a conclusion based on the results of the work.

Topic: “Determination of the floating conditions of a body.”

Goal: using Archimedes' law, determine the location of your body in the liquid.

Equipment: liter jar, bathroom scale, bathtub.

Progress:

1. Fill the bathtub with water and mark the water level along the edge.

2. Immerse yourself in the bath. The liquid level will increase. Make a mark along the edge.

3. Using a liter jar, determine your volume: it is equal to the difference in the volumes marked along the edge of the bath. Convert the result to the SI system.

4. Using Archimedes' law, determine the buoyant action of the liquid.

5. Using a bathroom scale, measure your mass and calculate your weight.

6. Compare your weight with the value of the Archimedean force and determine the location of your body in the liquid.

7. Illustrate the experiment performed by indicating the vectors of Archimedes’ weight and force.

8. Draw a conclusion based on the results of the work.

Topic: “Definition of work to overcome gravity.”

Purpose: using the work formula, determine the physical load of a person when making a jump.

Progress:

1. Use a ruler to determine the height of your jump.

3. Using the formula, determine the work required to complete the jump (all quantities must be expressed in the SI system).

Topic: “Determination of landing speed.”

Purpose: using the formulas of kinetic and potential energy, the law of conservation of energy, determine the landing speed when making a jump.

Equipment: floor scales, ruler.

Progress:

1. Use a ruler to determine the height of the chair from which the jump will be made.

2. Using a floor scale, determine your mass.

3. Using the formulas of kinetic and potential energy, the law of conservation of energy, derive a formula for calculating the landing speed when making a jump and perform the necessary calculations (all quantities must be expressed in the SI system).

4. Draw a conclusion about the results of the work.

Topic: “Mutual attraction of molecules”

Equipment: cardboard, scissors, bowl with cotton wool, dishwashing liquid.

Progress:

1. Cut out a boat in the shape of a triangular arrow from cardboard.

2. Pour water into a bowl.

3. Carefully place the boat on the surface of the water.

4. Dip your finger in dishwashing liquid.

5. Carefully place your finger in the water just behind the boat.

6. Describe observations.

7. Draw a conclusion.

Topic: “How various fabrics absorb moisture”

Equipment: various scraps of fabric, water, a tablespoon, a glass, a rubber band, scissors.

Progress:

1. Cut a 10x10 cm square from various pieces of fabric.

2. Cover the glass with these pieces.

3. Secure them to the glass with a rubber band.

4. Carefully pour a spoonful of water onto each piece.

5. Remove the flaps and pay attention to the amount of water in the glass.

6. Draw conclusions.

Topic: “Mixing immiscibles”

Equipment: plastic bottle or transparent disposable glass, vegetable oil, water, spoon, dishwashing liquid.

Progress:

1. Pour some oil and water into a glass or bottle.

2. Mix oil and water thoroughly.

3. Add some dishwashing liquid. Stir.

4. Describe observations.

Topic: “Determining the distance traveled from home to school”

Progress:

1. Select a route.

2. Approximately calculate the length of one step using a tape measure or measuring tape. (S1)

3. Calculate the number of steps when moving along the selected route (n).

4. Calculate the path length: S = S1 · n, in meters, kilometers, fill out the table.

5. Draw the route of movement to scale.

6. Draw a conclusion.

Topic: “Interaction of bodies”

Equipment: glass, cardboard.

Progress:

1. Place the glass on the cardboard.

2. Slowly pull on the cardboard.

3. Quickly pull out the cardboard.

4. Describe the movement of the glass in both cases.

5. Draw a conclusion.

Topic: “Calculating the density of a bar of soap”

Equipment: a bar of laundry soap, a ruler.

Progress:

3. Using a ruler, determine the length, width, height of the piece (in cm)

4. Calculate the volume of a bar of soap: V = a b c (in cm3)

5. Using the formula, calculate the density of a bar of soap: p = m/V

6. Fill out the table:

7. Convert density expressed in g/cm3 to kg/m3

8. Draw a conclusion.

Topic: “Is air heavy?”

Equipment: two identical balloons, a wire hanger, two clothespins, a pin, thread.

Progress:

1. Inflate two balloons to single size and tie with thread.

2. Hang the hanger on the handrail. (You can place a stick or mop on the backs of two chairs and attach a hanger to it.)

3. Attach a balloon to each end of the hanger with a clothespin. Balance.

4. Pierce one ball with a pin.

5. Describe the observed phenomena.

6. Draw a conclusion.

Topic: “Determination of mass and weight in my room”

Equipment: tape measure or measuring tape.

Progress:

1. Using a tape measure or measuring tape, determine the dimensions of the room: length, width, height, expressed in meters.

2. Calculate the volume of the room: V = a b c.

3. Knowing the air density, calculate the mass of air in the room: m = р·V.

4. Calculate the weight of air: P = mg.

5. Fill out the table:

6. Draw a conclusion.

Topic: “Feel the friction”

Equipment: dishwashing liquid.

Progress:

1. Wash your hands and dry them.

2. Quickly rub your palms together for 1-2 minutes.

3. Apply a little dishwashing liquid to your palms. Rub your palms again for 1-2 minutes.

4. Describe the observed phenomena.

5. Draw a conclusion.

Topic: “Determination of the dependence of gas pressure on temperature”

Equipment: balloon, thread.

Progress:

1. Inflate the balloon and tie it with thread.

2. Hang the ball outside.

3. After a while, pay attention to the shape of the ball.

4. Explain why:

a) By directing a stream of air when inflating a balloon in one direction, we force it to inflate in all directions at once.

b) Why not all balls take a spherical shape.

c) Why does the ball change its shape when the temperature decreases?

5. Draw a conclusion.

Topic: “Calculating the force with which the atmosphere presses on the surface of the table?”

Equipment: measuring tape.

Progress:

1. Using a tape measure or measuring tape, calculate the length and width of the table and express it in meters.

2. Calculate the area of ​​the table: S = a · b

3. Take the pressure from the atmosphere equal to Pat = 760 mm Hg. translate Pa.

4. Calculate the force acting from the atmosphere on the table:

P = F/S; F = P ·S; F = P a b

5. Fill out the table.

6. Draw a conclusion.

Topic: “Floats or sinks?”

Equipment: large bowl, water, paper clip, apple slice, pencil, coin, cork, potato, salt, glass.

Progress:

1. Pour water into a bowl or basin.

2. Carefully lower all the listed items into the water.

3. Take a glass of water and dissolve 2 tablespoons of salt in it.

4. Dip into the solution those objects that sank in the first one.

5. Describe observations.

6. Draw a conclusion.

Topic: “Calculating the work done by a student when climbing from the first to the second floor of a school or home”

Equipment: tape measure.

Progress:

1. Using a tape measure, measure the height of one step: So.

2. Calculate the number of steps: n

3. Determine the height of the stairs: S = So·n.

4. If possible, determine your body weight; if not, take approximate data: m, kg.

5. Calculate the gravity of your body: F = mg

6. Define work: A = F·S.

7. Fill out the table:

8. Draw a conclusion.

Topic: “Determination of the power that a student develops by uniformly rising slowly and quickly from the first to the second floor of a school or home”

Equipment: data from the work “Calculating the work done by a student when climbing from the first to the second floor of a school or home,” stopwatch.

Progress:

1. Using the data from the work “Calculating the work done by a student when climbing from the first to the second floor of a school or home,” determine the work done when climbing the stairs: A.

2. Using a stopwatch, determine the time spent slowly climbing the stairs: t1.

3. Using a stopwatch, determine the time spent quickly climbing the stairs: t2.

4. Calculate the power in both cases: N1, N2, N1 = A/t1, N2 = A/t2

5. Write the results in the table:

6. Draw a conclusion.

Topic: “Finding out the equilibrium conditions of a lever”

Equipment: ruler, pencil, eraser, old coins (1 k, 2 k, 3 k, 5 k).

Progress:

1. Place a pencil under the middle of the ruler so that the ruler is in balance.

2. Place an elastic band on one end of the ruler.

3. Balance the lever using coins.

4. Considering that the mass of old-style coins is 1 k - 1 g, 2 k - 2 g, 3 k - 3 g, 5 k - 5 g. Calculate the mass of the rubber band, m1, kg.

5. Move the pencil to one end of the ruler.

6. Measure shoulders l1 and l2, m.

7. Balance the lever using coins m2, kg.

8. Determine the forces acting on the ends of the lever F1 = m1g, F2 = m2g

9. Calculate the moment of forces M1 = F1l1, M2 = P2l2

10. Fill out the table.

11. Draw a conclusion.

Bibliographic link

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 fantastic stories, show entertaining experiments, and cite biographies of great scientists as examples.

How to conduct physics experiments with children?

• Teachers warn that acquaintance with physical phenomena should not be limited only to the demonstration of entertaining experiences and experiments.
• Experiments must be accompanied by detailed explanations.
• First, the child must be explained that physics is a science that studies the general laws of 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 filled with cold water. It will immediately end up at the bottom. Fill the second glass with 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 your child, you can see 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: a glass bottle, a bowl of colored water and hot water.

Using hot water, warm up the bottle. Pour hot water out of it 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 experience 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 a plexiglass ruler becomes a source of an 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), carbon dioxide is released, which is what causes the spoon to 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 children about the physical properties of a 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 cold water in a saucer 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!

In school physics lessons, teachers always say that physical phenomena are everywhere in our lives. Only we often forget about this. Meanwhile, amazing things are nearby! Don't think that you need anything extravagant to organize physical experiments at home. And here's some proof for you ;)

Magnetic pencil

What needs to be prepared?

• Battery.
• Thick pencil.
• Insulated copper wire with a diameter of 0.2–0.3 mm and a length of several meters (the longer, the better).
• Scotch.

Conducting the experiment

Wind the wire tightly, turn to turn, around the pencil, 1 cm short of its edges. When one row ends, wind another on top in the opposite direction. And so on until all the wire runs out. Don’t forget to leave two ends of the wire, 8–10 cm each, free. To prevent the turns 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 bringing small iron objects to it - a paper clip, a hairpin. They are attracted!

Lord of Water

What needs to be prepared?

• A plexiglass stick (for example, a student’s ruler or a regular plastic comb).
• A dry cloth made of silk or wool (for example, a wool sweater).

Conducting the experiment

Open the tap so that a thin stream of water flows. Rub the stick or comb vigorously on the prepared cloth. Quickly bring the stick closer to the stream of water without touching it.

What will 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.

Top

What needs to be prepared?

• Paper, needle and eraser.
• A stick and a dry woolen cloth from previous experience.

Conducting the experiment

You can control more than just water! Cut a strip of paper 1–2 cm wide and 10–15 cm long, bend it along the edges and in the middle, as shown in the picture. Insert the sharp end of the needle into the eraser. Balance the top workpiece on the needle. Prepare a “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 will happen?

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

Ice and fire

(the experiment is carried out on a sunny day)

What needs to be prepared?

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

Conducting the experiment

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

What will happen?

The paper should be charred, because it’s not just ice in your hands anymore... Did you guess that you made a magnifying glass?

Wrong mirror

What needs to be prepared?

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

Conducting the experiment

Fill the jar with excess water and close the lid to prevent air bubbles from getting inside. Place the jar with the lid facing up against the mirror. Now you can look in the “mirror”.

Bring your face closer and look inside. There will be a thumbnail image. Now start tilting the jar to the side without lifting it from the mirror.

What will happen?

The reflection of your head in the jar, of course, will also tilt until it turns upside down, and your legs will still not be visible. Lift the can and the reflection will turn over again.

Cocktail with bubbles

What needs to be prepared?

• A glass with a strong solution of table salt.
• A battery from a flashlight.
• Two pieces of copper wire approximately 10 cm long.
• Fine sandpaper.

Conducting the experiment

Clean the ends of the wire with fine sandpaper. Connect one end of the wire to each pole of the battery. Dip the free ends of the wires into a glass with the 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.
• Steel paper clip.
• A light bulb from a flashlight.

Conducting the experiment

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

What will happen?

The light will light up!

Introduction

Without a doubt, all our knowledge begins with experiments.
(Kant Emmanuel. German philosopher g.)

Physics experiments introduce students to the diverse applications of the laws of physics in a fun way. Experiments can be used in lessons to attract students’ attention to the phenomenon being studied, when repeating and consolidating educational material, and at physical evenings. Entertaining experiences deepen and expand students' knowledge, promote the development of logical thinking, and instill interest in the subject.

The role of experiment in the science of physics

The fact that physics is a young science
It’s impossible to say for sure here.
And in ancient times, learning science,
We always strived to comprehend it.

The purpose of teaching physics is specific,
Be able to apply all knowledge in practice.
And it’s important to remember – the role of experiment
Must stand first.

Be able to plan an experiment and carry it out.
Analyze and bring to life.
Build a model, put forward a hypothesis,
Striving to reach new heights

The laws of physics are based on facts established empirically. Moreover, the interpretation of the same facts often changes in the course of the historical development of physics. Facts accumulate through observation. But you can’t limit yourself to them only. 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 and find out the causes of phenomena, it is necessary to establish quantitative relationships between quantities. If such a dependence is obtained, then a physical law has been found. If a physical law is found, then there is no need to experiment in each individual case; it is enough to perform the appropriate calculations. By experimentally studying quantitative relationships between quantities, patterns can be identified. Based on these laws, a general theory of phenomena is developed.

Therefore, without experiment there can be no rational teaching of physics. The study of physics involves the widespread use of experiments, discussion of the features of its setting and the observed results.

Entertaining experiments in physics

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

Name of the experiment Equipment and materials required for the experiment Stages of the experiment Explanation of the experiment

Experiment No. 1 Four floors

Devices 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 do not mix and stand five levels above each other. However, it will be more convenient for us to take not a glass, but a narrow glass that widens towards the top.

Pour salted tinted water into the bottom of the glass. Roll up a “Funtik” from paper and bend its end at a right angle; cut off the tip. The hole in the Funtik should be the size of a pinhead. Pour red wine into this cone; a thin stream should flow out of it horizontally, break against the walls of the glass and flow down it 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. From the second cone, pour sunflower oil into a glass in the same way. From the third horn, pour a layer of colored alcohol.

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Experience No. 2 Amazing candlestick

Devices 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.

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Figure 3

Explanation of experience

The candle goes out because the bottle is “flown around” with air: the stream of air is broken by the bottle into two streams; one flows around it on the right, and the other on the left; and they meet approximately where the candle flame stands.

Experiment No. 4 Spinning snake

Devices and materials: thick paper, candle, scissors.

Stages of the experiment

Cut a spiral out of thick paper, stretch it a little and place it on the end of a curved wire. Hold this spiral above the candle in the rising air flow, the snake will rotate.

Explanation of experience

The snake rotates because air expands under the influence of heat and warm energy is converted into movement.

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Figure 5

Explanation of experience

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

Experiment No. 6 Fifteen matches on one

Devices and materials: 15 matches.

Stages of the experiment

Place one match on the table, and 14 matches across it so that their heads stick up and their ends touch the table. How to lift the first match, holding it by one end, and all the other matches along with it?

Explanation of experience

To do this, you just need to put another fifteenth match on top of all the matches, in the hollow between them.

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Figure 7

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Figure 9

Experience No. 8 Paraffin motor

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

Stages of the experiment

To make this motor, we don't need either electricity or gasoline. 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 a candle with a knitting needle on the edges of two glasses and balance. Light the candle at both ends.

Explanation of experience

A drop of paraffin will fall into one of the plates placed under the ends of the candle. The balance will be disrupted, the other end of the candle will tighten and fall; 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, it will become lighter, and our motor will start working with all its might; gradually the candle's vibrations will increase more and more.

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Figure 11

Demonstration experiments

1. Diffusion of liquids and gases

Diffusion (from Latin diflusio - spreading, spreading, scattering), the transfer of particles of different nature, caused by 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, diffusion observation device.

Stages of the experiment

Let's take two pieces of cotton wool. We moisten one piece of cotton wool with phenolphthalein, the other with ammonia. Let's bring the branches into contact. The fleeces are observed to turn pink due to the phenomenon of diffusion.

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Figure 13

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Figure 15

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

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Figure 17

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Figure 19

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Figure 21

3.Pascal's ball

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

To demonstrate the uniform transfer of pressure exerted on a liquid in a closed vessel, it is necessary to use a piston to draw water into the vessel and place the ball tightly on the nozzle. By pushing the piston into the vessel, demonstrate the flow of liquid from the holes in the ball, paying attention to the uniform flow of liquid in all directions.