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Topic: DIY physics devices and simple experiments with them.

Work completed by: 9th grade student - Roma Davydov Supervisor: physics teacher - Khovrich Lyubov Vladimirovna

Novouspenka – 2008

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Make a device, a physics installation to demonstrate physical phenomena with your own hands. Explain the operating principle of this device. Demonstrate the operation of this device.

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HYPOTHESIS:

Use the made device, a physics installation for demonstrating physical phenomena with your own hands in the lesson. If this device is not available in the physical laboratory, this device will be able to replace the missing installation when demonstrating and explaining the topic.

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Make devices that arouse great interest among students. Make devices that are not available in the laboratory. make devices that cause difficulty in understanding theoretical material in physics.

Slide 5

With uniform rotation of the handle, we see that the action of a periodically changed force will be transmitted to the load through the spring. Changing with a frequency equal to the frequency of rotation of the handle, this force will force the load to perform forced vibrations. Resonance is the phenomenon of a sharp increase in the amplitude of forced vibrations.

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EXPERIENCE 2: Jet propulsion

We will install a funnel in a ring on a tripod and attach a tube with a tip to it. We pour water into the funnel, and when the water begins to flow out from the end, the tube will bend in the opposite direction. This is reactive movement. Reactive motion is the movement of a body that occurs when some part of it is separated from it at any speed.

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EXPERIMENT 3: Sound waves.

Let's clamp a metal ruler in a vice. But it is worth noting that if most of the ruler acts as a vice, then, having caused it to oscillate, we will not hear the waves generated by it. But if we shorten the protruding part of the ruler and thereby increase the frequency of its oscillations, then we will hear the generated Elastic waves, propagating in the air, as well as inside liquid and solid bodies, but are not visible. However, under certain conditions they can be heard.

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Experiment 4: Coin in a bottle

Coin in a bottle. Want to see the law of inertia in action? Prepare a half-liter milk bottle, a cardboard ring 25 mm wide and 0 100 mm wide and a two-kopeck coin. Place the ring on the neck of the bottle, and place a coin on top exactly opposite the hole in the neck of the bottle (Fig. 8). After inserting a ruler into the ring, hit the ring with it. If you do this abruptly, the ring will fly off and the coin will fall into the bottle. The ring moved so quickly that its movement did not have time to be transferred to the coin, and according to the law of inertia, it remained in place. And having lost its support, the coin fell down. If the ring is moved to the side more slowly, the coin will “feel” this movement. The trajectory of its fall will change, and it will not fall into the neck of the bottle.

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Experiment 5: Floating Ball

When you blow, a stream of air lifts the balloon above the tube. But the air pressure inside the jet is less than the pressure of the “quiet” air surrounding the jet. Therefore, the ball is located in a kind of air funnel, the walls of which are formed by the surrounding air. By smoothly reducing the speed of the jet from the upper hole, it is not difficult to “plant” the ball in its original place. For this experiment you will need an L-shaped tube, for example glass, and a light foam ball. Close the top hole of the tube with a ball (Fig. 9) and blow into the side hole. Contrary to expectation, the ball will not fly away from the tube, but will begin to hover above it. Why is this happening?

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Experiment 6: Body movement in a “dead loop”

"Using the "dead loop" device, it is possible to demonstrate a number of experiments on the dynamics of a material point along a circle. The demonstration is carried out in the following order: 1. The ball is rolled along the rails from the highest point of the inclined rails, where it is held by an electromagnet, which is powered by 24 V. The ball steadily describes loop and flies out at a certain speed from the other end of the device2. The ball is rolled down from the lowest height, when the ball just describes the loop without falling off from its top point3. From an even lower height, when the ball, not reaching the top of the loop, breaks away from it and falls, describing a parabola in the air inside the loop.

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Body movement in a "dead loop"

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Experiment 7: Hot air and cold air

Stretch a balloon onto the neck of an ordinary half-liter bottle (Fig. 10). Place the bottle in a pan of hot water. The air inside the bottle will begin to heat up. The molecules of the gases that make up it will move faster and faster as the temperature rises. They will bombard the walls of the bottle and ball more strongly. The air pressure inside the bottle will begin to increase and the balloon will begin to inflate. After a while, transfer the bottle to a pan of cold water. The air in the bottle will begin to cool, the movement of molecules will slow down, and the pressure will drop. The ball will wrinkle as if the air has been pumped out of it. This is how you can verify the dependence of air pressure on ambient temperature

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Experiment 8: Tension of a rigid body

Taking the foam block by the ends, stretch it. The increase in distances between molecules is clearly visible. It is also possible to simulate the occurrence of inter-molecular attractive forces in this case.

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 fancy 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 woolen sweater).

Conducting the experiment

Open the tap so that a thin stream of water flows. Rub the stick or comb firmly 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 flashlight bulb.

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 attach them to the contacts of the light bulb.

What will happen?

The light will light up!

a- Roma Davydov Head: physics teacher - Khovrich Lyubov Vladimirovna Novouspenka – 2008

Goal: Make a device, a physics installation to demonstrate physical phenomena with your own hands. Explain the operating principle of this device. Demonstrate the operation of this device.

HYPOTHESIS: Use the made device, installation in physics to demonstrate physical phenomena with your own hands in the lesson. If this device is not available in the physical laboratory, this device will be able to replace the missing installation when demonstrating and explaining the topic.

Objectives: Make devices that arouse great interest among students. Make devices that are not available in the laboratory. make devices that cause difficulty in understanding theoretical material in physics.

EXPERIMENT 1: Forced oscillations. With uniform rotation of the handle, we see that the action of a periodically changed force will be transmitted to the load through the spring. Changing with a frequency equal to the frequency of rotation of the handle, this force will force the load to perform forced vibrations. Resonance is the phenomenon of a sharp increase in the amplitude of forced vibrations.

Forced vibrations

EXPERIENCE 2: Jet propulsion. We will install a funnel in a ring on a tripod and attach a tube with a tip to it. We pour water into the funnel, and when the water begins to flow out from the end, the tube will bend in the opposite direction. This is reactive movement. Reactive motion is the movement of a body that occurs when some part of it is separated from it at any speed.

Jet propulsion

EXPERIMENT 3: Sound waves. Let's clamp a metal ruler in a vice. But it is worth noting that if most of the ruler acts as a vice, then, having caused it to oscillate, we will not hear the waves generated by it. But if we shorten the protruding part of the ruler and thereby increase the frequency of its oscillations, then we will hear the generated Elastic waves, propagating in the air, as well as inside liquid and solid bodies, but are not visible. However, under certain conditions they can be heard.

Sound waves.

Experiment 4: Coin in a bottle Coin in a bottle. Want to see the law of inertia in action? Prepare a half-liter milk bottle, a cardboard ring 25 mm wide and 0 100 mm wide and a two-kopeck coin. Place the ring on the neck of the bottle, and place a coin on top exactly opposite the hole in the neck of the bottle (Fig. 8). After inserting a ruler into the ring, hit the ring with it. If you do this abruptly, the ring will fly off and the coin will fall into the bottle. The ring moved so quickly that its movement did not have time to be transferred to the coin, and according to the law of inertia, it remained in place. And having lost its support, the coin fell down. If the ring is moved to the side more slowly, the coin will “feel” this movement. The trajectory of its fall will change, and it will not fall into the neck of the bottle.

Coin in a bottle

Experiment 5: Floating Ball When you blow, a stream of air lifts the ball above the tube. But the air pressure inside the jet is less than the pressure of the “quiet” air surrounding the jet. Therefore, the ball is located in a kind of air funnel, the walls of which are formed by the surrounding air. By smoothly reducing the speed of the jet from the upper hole, it is not difficult to “plant” the ball in its original place. For this experiment you will need an L-shaped tube, for example glass, and a light foam ball. Close the top hole of the tube with a ball (Fig. 9) and blow into the side hole. Contrary to expectation, the ball will not fly away from the tube, but will begin to hover above it. Why is this happening?

floating ball

Experiment 6: Movement of a body along a “dead loop” Using the “dead loop” device, you can demonstrate a number of experiments on the dynamics of a material point along a circle. The demonstration is carried out in the following order: 1. The ball is rolled down the rails from the highest point of the inclined rails, where it is held by an electromagnet, which is powered by 24V. The ball steadily describes a loop and flies out at a certain speed from the other end of the device2. The ball is rolled down from the lowest height when the ball just describes the loop without falling off its top point3. From an even lower height, when the ball, not reaching the top of the loop, breaks away from it and falls, describing a parabola in the air inside the loop.

Body movement in a "dead loop"

Experiment 7: Hot air and cold air Stretch a balloon onto the neck of an ordinary half-liter bottle (Fig. 10). Place the bottle in a pan of hot water. The air inside the bottle will begin to heat up. The molecules of the gases that make up it will move faster and faster as the temperature rises. They will bombard the walls of the bottle and ball more strongly. The air pressure inside the bottle will begin to increase and the balloon will begin to inflate. After a while, transfer the bottle to a pan of cold water. The air in the bottle will begin to cool, the movement of molecules will slow down, and the pressure will drop. The ball will wrinkle as if the air has been pumped out of it. This is how you can verify the dependence of air pressure on ambient temperature

The air is hot and the air is cold

Experiment 8: Stretching a solid body Taking the foam block by the ends, stretch it. The increase in distances between molecules is clearly visible. It is also possible to simulate the occurrence of inter-molecular attractive forces in this case.

Tension of a rigid body

Experiment 9: Compression of a solid body Compress a foam block along its major axis. To do this, place it on a stand, cover the top with a ruler and apply pressure with your hand. A decrease in the distance between the molecules and the emergence of repulsive forces between them are observed.

Compression of a solid

Experiment 4: Double cone rolling upward. This experiment serves to demonstrate experience confirming that a freely moving object is always positioned in such a way that the center of gravity occupies the lowest possible position for it. Before demonstration, the planks are placed at a certain angle. To do this, the double cone is placed with its ends into the cutouts made in the upper edge of the planks. Then the cone is moved down to the beginning of the planks and released. The cone will move upward until its ends fall into the cutouts. In fact, the center of gravity of the cone, lying on its axis, will shift downward, which is what we see.

Double cone rolling upward

Student interest in a lesson with physics experience

Conclusion: It is interesting to observe the experiment conducted by the teacher. Carrying it out yourself is doubly more interesting. And conducting an experiment with a device made and designed by yourself arouses great interest among the whole class. In such experiments it is easy to establish a relationship and draw a conclusion about how this installation works.

Do you love physics? You love experiment? The world of physics is waiting for you!
What could be more interesting than experiments in physics? And, of course, the simpler the better!
These exciting experiments will help you see extraordinary phenomena light and sound, electricity and magnetism Everything necessary for the experiments is easy to find at home, and the experiments themselves simple and safe.
Your eyes are burning, your hands are itching!
Go ahead, explorers!

Robert Wood - a genius of experimentation.........
- Up or down? Rotating chain. Fingers of salt......... - Moon and diffraction. What color is the fog? Newton's rings......... - A top in front of the TV. Magic propeller. Ping-pong in the bath......... - Spherical aquarium - lens. Artificial mirage. Soap glasses......... - Eternal salt fountain. Fountain in a test tube. Rotating spiral......... - Condensation in a jar. Where is the water vapor? Water engine........ - Popping egg. An overturned glass. Swirl in a cup. Heavy newspaper.........
- IO-IO toy. Salt pendulum. Paper dancers. Electric dance.........
- The mystery of ice cream. Which water will freeze faster? It's frosty, but the ice is melting! .......... - Let's make a rainbow. A mirror that doesn't confuse. Microscope made from a drop of water.........
- The snow creaks. What will happen to the icicles? Snow flowers......... - Interaction of sinking objects. Ball is touchable.........
- Who is faster? Jet balloon. Air carousel......... - Bubbles from a funnel. Green hedgehog. Without opening the bottles......... - Spark plug motor. Bump or hole? A moving rocket. Divergent rings.........
- Multi-colored balls. Sea resident. Balancing egg.........
- Electric motor in 10 seconds. Gramophone..........
- Boil, cool......... - Waltzing dolls. Flame on paper. Robinson's feather.........
- Faraday experiment. Segner wheel. Nutcrackers......... - Dancer in the mirror. Silver plated egg. Trick with matches......... - Oersted's experience. Roller coaster. Don't drop it! ..........

Body weight. Weightlessness.
Experiments with weightlessness. Weightless water. How to reduce your weight.........

Elastic force
- Jumping grasshopper. Jumping ring. Elastic coins..........
Friction
- Reel-crawler..........
- Drowned thimble. Obedient ball. We measure friction. Funny monkey. Vortex rings.........
- Rolling and sliding. Rest friction. The acrobat is doing a cartwheel. Brake in the egg.........
Inertia and inertia
- Take out the coin. Experiments with bricks. Wardrobe experience. Experience with matches. Inertia of the coin. Hammer experience. Circus experience with a jar. Experiment with a ball.........
- Experiments with checkers. Domino experience. Experiment with an egg. Ball in a glass. Mysterious skating rink.........
- Experiments with coins. Water hammer. Outsmarting inertia.........
- Experience with boxes. Experience with checkers. Coin experience. Catapult. Inertia of an apple.........
- Experiments with rotational inertia. Experiment with a ball.........

Mechanics. Laws of mechanics
- Newton's first law. Newton's third law. Action and reaction. Law of conservation of momentum. Quantity of movement.........

Jet propulsion
- Jet shower. Experiments with jet spinners: air spinner, jet balloon, ether spinner, Segner wheel.........
- Balloon rocket. Multistage rocket. Pulse ship. Jet boat.........

Free fall
-Which is faster.........

Circular movement
- Centrifugal force. Easier on turns. Experience with the ring.........

Rotation
- Gyroscopic toys. Clark's top. Greig's top. Lopatin's flying top. Gyroscopic machine.........
- Gyroscopes and tops. Experiments with a gyroscope. Experience with a top. Wheel experience. Coin experience. Riding a bike without hands. Boomerang experience.........
- Experiments with invisible axes. Experience with paper clips. Rotating a matchbox. Slalom on paper.........
- Rotation changes shape. Cool or damp. Dancing egg. How to put a match.........
- When the water does not pour out. A bit of a circus. Experiment with a coin and a ball. When the water pours out. Umbrella and separator..........

Statics. Equilibrium. Center of gravity
- Vanka-stand up. Mysterious nesting doll.........
- Center of gravity. Equilibrium. Center of gravity height and mechanical stability. Base area and balance. Obedient and naughty egg..........
- Center of gravity of a person. Balance of forks. Fun swing. A diligent sawyer. Sparrow on a branch.........
- Center of gravity. Pencil competition. Experience with unstable balance. Human balance. Stable pencil. Knife at the top. Experience with a ladle. Experience with a saucepan lid.........

Structure of matter
- Fluid model. What gases does air consist of? Highest density of water. Density tower. Four floors.........
- Plasticity of ice. A nut that has come out. Properties of non-Newtonian fluid. Growing crystals. Properties of water and eggshells..........

Thermal expansion
- Expansion of a solid. Lapped plugs. Needle extension. Thermal scales. Separating glasses. Rusty screw. The board is in pieces. Ball expansion. Coin expansion.........
- Expansion of gas and liquid. Heating the air. Sounding coin. Water pipe and mushrooms. Heating water. Warming up the snow. Dry from the water. The glass is creeping.........

Surface tension of a liquid. Wetting
- Plateau experience. Darling's experience. Wetting and non-wetting. Floating razor.........
- Attraction of traffic jams. Sticking to water. A miniature Plateau experience. Bubble..........
- Live fish. Paperclip experience. Experiments with detergents. Colored streams. Rotating spiral.........

Capillary phenomena
- Experience with a blotter. Experiment with pipettes. Experience with matches. Capillary pump.........

Bubble
- Hydrogen soap bubbles. Scientific preparation. Bubble in a jar. Colored rings. Two in one..........

Energy
- Transformation of energy. Bent strip and ball. Tongs and sugar. Photo exposure meter and photo effect.........
- Conversion of mechanical energy into thermal energy. Propeller experience. Bogatyr in a thimble..........

Thermal conductivity
- Experiment with an iron nail. Experience with wood. Experience with glass. Experiment with spoons. Coin experience. Thermal conductivity of porous bodies. Thermal conductivity of gas.........

Heat
-Which is colder. Heating without fire. Absorption of heat. Radiation of heat. Evaporative cooling. Experiment with an extinguished candle. Experiments with the outer part of the flame..........

Radiation. Energy transfer
- Transfer of energy by radiation. Experiments with solar energy.........

Convection
- Weight is a heat regulator. Experience with stearin. Creating traction. Experience with scales. Experience with a turntable. Pinwheel on a pin..........

Aggregate states.
- Experiments with soap bubbles in the cold. Crystallization
- Frost on the thermometer. Evaporation from the iron. We regulate the boiling process. Instant crystallization. growing crystals. Making ice. Cutting ice. Rain in the kitchen.........
- Water freezes water. Ice castings. We create a cloud. Let's make a cloud. We boil the snow. Ice bait. How to get hot ice.........
- Growing crystals. Salt crystals. Golden crystals. Large and small. Peligo's experience. Experience-focus. Metal crystals.........
- Growing crystals. Copper crystals. Fairytale beads. Halite patterns. Homemade frost.........
- Paper pan. Dry ice experiment. Experience with socks.........

Gas laws
- Experience on the Boyle-Mariotte law. Experiment on Charles's law. Let's check the Clayperon equation. Let's check Gay-Lusac's law. Ball trick. Once again about the Boyle-Mariotte law..........

Engines
- Steam engine. The experience of Claude and Bouchereau.........
- Water turbine. Steam turbine. Wind engine. Water wheel. Hydro turbine. Windmill toys.........

Pressure
- Pressure of a solid body. Punching a coin with a needle. Cutting through ice.........
- Siphon - Tantalus vase..........
- Fountains. The simplest fountain. Three fountains. Fountain in a bottle. Fountain on the table.........
- Atmosphere pressure. Bottle experience. Egg in a decanter. Can sticking. Experience with glasses. Experience with a can. Experiments with a plunger. Flattening the can. Experiment with test tubes.........
- Vacuum pump made from blotting paper. Air pressure. Instead of the Magdeburg hemispheres. A diving bell glass. Carthusian diver. Punished curiosity.........
- Experiments with coins. Experiment with an egg. Experience with a newspaper. School gum suction cup. How to empty a glass.........
- Pumps. Spray..........
- Experiments with glasses. The mysterious property of radishes. Experience with a bottle.........
- Naughty plug. What is pneumatics? Experiment with a heated glass. How to lift a glass with your palm.........
- Cold boiling water. How much does water weigh in a glass? Determine lung volume. Resistant funnel. How to pierce a balloon without it bursting..........
- Hygrometer. Hygroscope. Barometer from a cone......... - Barometer. Aneroid barometer - do it yourself. Balloon barometer. The simplest barometer......... - Barometer from a light bulb.......... - Air barometer. Water barometer. Hygrometer..........

Communicating vessels
- Experience with the painting.........

Archimedes' law. Buoyancy force. Floating bodies
- Three balls. The simplest submarine. Grape experiment. Does iron float.........
- Ship's draft. Does the egg float? Cork in a bottle. Water candlestick. Sinks or floats. Especially for drowning people. Experience with matches. Amazing egg. Does the plate sink? The mystery of the scales.........
- Float in a bottle. Obedient fish. Pipette in a bottle - Cartesian diver..........
- Ocean level. Boat on the ground. Will the fish drown? Stick scales.........
- Archimedes' Law. Live toy fish. Bottle level.........

Bernoulli's law
- Experience with a funnel. Experiment with water jet. Ball experiment. Experience with scales. Rolling cylinders. stubborn leaves.........
- Bendable sheet. Why doesn't he fall? Why does the candle go out? Why doesn't the candle go out? The air flow is to blame.........

Simple mechanisms
- Block. Pulley hoist.........
- Lever of the second type. Pulley hoist.........
- Lever arm. Gate. Lever scales.........

Oscillations
- Pendulum and bicycle. Pendulum and globe. A fun duel. Unusual pendulum..........
- Torsion pendulum. Experiments with a swinging top. Rotating pendulum.........
- Experiment with the Foucault pendulum. Addition of vibrations. Experiment with Lissajous figures. Resonance of pendulums. Hippopotamus and bird.........
- Fun swing. Oscillations and resonance.........
- Fluctuations. Forced vibrations. Resonance. Seize the moment.........

Sound
- Gramophone - do it yourself..........
- Physics of musical instruments. String. Magic bow. Ratchet. Singing glasses. Bottlephone. From bottle to organ.........
- Doppler effect. Sound lens. Chladni's experiments.........
- Sound waves. Propagation of sound.........
- Sounding glass. Flute made from straw. The sound of a string. Reflection of sound.........
- Phone made from a matchbox. Telephone exchange.........
- Singing combs. Spoon ringing. Singing glass.........
- Singing water. Shy wire.........
- Sound oscilloscope..........
- Ancient sound recording. Cosmic voices.........
- Hear the heartbeat. Glasses for ears. Shock wave or firecracker..........
- Sing with me. Resonance. Sound through the bone.........
- Tuning fork. A storm in a teacup. Louder sound.........
- My strings. Changing the pitch of the sound. Ding Ding. Crystal clear.........
- We make the ball squeak. Kazoo. Singing bottles. Choral singing..........
- Intercom. Gong. Crowing glass.........
- Let's blow out the sound. Stringed instrument. Small hole. Blues on bagpipes.........
- Sounds of nature. Singing straw. Maestro, march.........
- A speck of sound. What's in the bag? Sound on the surface. Day of disobedience.........
- Sound waves. Visual sound. Sound helps you see.........

Electrostatics
- Electrification. Electric panty. Electricity is repellent. Dance of soap bubbles. Electricity on combs. The needle is a lightning rod. Electrification of the thread.........
- Bouncing balls. Interaction of charges. Sticky ball.........
- Experience with a neon light bulb. Flying bird. Flying butterfly. An animated world.........
- Electric spoon. St. Elmo's Fire. Electrification of water. Flying cotton wool. Electrification of a soap bubble. Loaded frying pan.........
- Electrification of the flower. Experiments on human electrification. Lightning on the table.........
- Electroscope. Electric Theater. Electric cat. Electricity attracts.........
- Electroscope. Bubble. Fruit battery. Fighting gravity. Battery of galvanic cells. Connect the coils.........
- Turn the arrow. Balancing on the edge. Repelling nuts. Turn on the light.........
- Amazing tapes. Radio signal. Static separator. Jumping grains. Static rain.........
- Film wrapper. Magic figurines. Influence of air humidity. An animated door handle. Sparkling clothes.........
- Charging from a distance. Rolling ring. Crackling and clicking sounds. Magic wand..........
- Everything can be charged. Positive charge. Attraction of bodies. Static glue. Charged plastic. Ghost leg.........

Summary: Coin and balloon experiment. Entertaining physics for children. Fascinating physics. Do-it-yourself physics experiments. Entertaining experiments in physics.

This experiment is a wonderful example of the action of centrifugal and centripetal forces.

To conduct the experiment you will need:

A balloon (preferably a pale color, so that when inflated it is as transparent as possible) - a coin - threads

Work plan:

1. Place a coin inside the ball.

2. Inflate the balloon.

3. Tie it with thread.

4. Take the ball with one hand by the end where the thread is. Make several rotational movements with your hand.

5. After some time, the coin will begin to rotate in a circle inside the ball.

6. Now with your other hand, fix the ball from below in a stationary position.

7. The coin will continue to spin for another 30 seconds or more.

Explanation of experience:

When an object rotates, a force called centrifugal force occurs. Have you ridden the carousel? You felt a force throwing you outward from the axis of rotation. This is centrifugal force. When you spin the ball, a centrifugal force acts on the coin, which presses it against the inner surface of the ball. At the same time, the ball itself acts on it, creating a centripetal force. The interaction of these two forces causes the coin to spin around.