Physical experience. A ball that doesn't burn! Testing the ability to attract various objects

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, at physical evenings. Entertaining experiments deepen and expand students’ knowledge, contribute to the development logical thinking, 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 during historical development 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 quality characteristics. To draw from observations general conclusions, to find out the causes of the 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 patterns, it develops general theory phenomena.

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 pin head. 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 into the glass in the same way. sunflower oil. 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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Devices and materials: thin glass, water.

Stages of the experiment

Fill a glass with water and wipe the edges of the glass. Rub a moistened finger anywhere on the glass and she will start singing.

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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 stained in pink color 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.

Experiments at home are great way introduce children to the basics of physics and chemistry, and facilitate understanding of complex abstract laws and terms with the help of visual demonstrations. Moreover, to carry them out you do not need to acquire expensive reagents or special equipment. After all, without thinking, we carry out experiments every day at home - from adding slaked soda to dough to connecting batteries to a flashlight. Read on to learn how to conduct interesting experiments easily, simply, and safely.

Chemical experiments at home

Does the image of a professor with a glass flask and singed eyebrows immediately come to mind? Don't worry, ours chemical experiments at home are completely safe, interesting and useful. Thanks to them, the child will easily remember what exo- and endothermic reactions are and what the difference is between them.

So let's make hatchable dinosaur eggs that can be used as bath bombs.

For the experience you need:

• small dinosaur figurines;
• baking soda;
• vegetable oil;
• lemon acid;
• food coloring or liquid watercolor paints.

Procedure for conducting the experiment

1. Place ½ cup baking soda in a small bowl and add about ¼ tsp. liquid paints(or dissolve 1-2 drops food coloring in ¼ teaspoon water), stir the baking soda with your fingers to create an even color.
2. Add 1 tbsp. l. citric acid. Mix dry ingredients thoroughly.
3. Add 1 tsp. vegetable oil.
4. You should have a crumbly dough that barely sticks together when pressed. If it doesn’t want to stick together at all, then slowly add ¼ tsp. butter until you reach the desired consistency.
5. Now take the dinosaur figurine and mold the dough into an egg shape. It will be very fragile at first, so you should set it aside overnight (at least 10 hours) to harden.
6. Then you can start a fun experiment: fill the bathtub with water and throw an egg into it. It will fizz furiously as it dissolves in the water. It will be cold when touched because it is an endothermic reaction between an acid and alkali, absorbing heat from the environment.

Please note that the bath may become slippery due to the addition of oil.

Elephant toothpaste

Experiments at home, the results of which can be felt and touched, are very popular with children. These include this fun project that ends big amount dense lush colored foam.

To carry it out you will need:

• safety glasses for children;
• dry active yeast;
• warm water;
• hydrogen peroxide 6%;
• dishwashing detergent or liquid soap (not antibacterial);
• funnel;
• plastic glitter (necessarily non-metallic);
• food colorings;
• 0.5 liter bottle (it is best to take a bottle with a wide bottom for greater stability, but a regular plastic one will do).

The experiment itself is extremely simple:

1. 1 tsp. dilute dry yeast in 2 tbsp. l. warm water.
2. In a bottle placed in a sink or dish with high sides, pour ½ cup of hydrogen peroxide, a drop of dye, glitter and a little dishwashing liquid (several presses on the dispenser).
3. Insert the funnel and pour in the yeast. The reaction will begin immediately, so act quickly.

The yeast acts as a catalyst and accelerates the release of hydrogen peroxide, and when the gas reacts with soap, it creates a huge amount of foam. This is an exothermic reaction, releasing heat, so if you touch the bottle after the “eruption” has stopped, it will be warm. Since the hydrogen immediately evaporates, all that remains is simply lather, with which you can play.

Physics experiments at home

Did you know that lemon can be used as a battery? True, very low-power. Experiments at home with citrus fruits will demonstrate to children the operation of a battery and a closed electrical circuit.

For the experiment you will need:

• lemons - 4 pcs.;
• galvanized nails - 4 pcs.;
• small pieces of copper (you can take coins) - 4 pcs.;
• alligator clips with short wires (about 20 cm) - 5 pcs.;
• small light bulb or flashlight - 1 pc.

Let there be light

Here's how to do the experiment:

1. Roll on a hard surface, then squeeze the lemons lightly to release the juice inside the skins.
2. Insert one galvanized nail and one piece of copper into each lemon. Place them on the same line.
3. Connect one end of the wire to a galvanized nail and the other to a piece of copper in another lemon. Repeat this step until all the fruits are connected.
4. When you're done, you should be left with 1 nail and 1 piece of copper that are not connected to anything. Prepare your light bulb, determine the polarity of the battery.
5. Connect the remaining piece of copper (plus) and the nail (minus) to the plus and minus of the flashlight. Thus, a chain of connected lemons is a battery.
6. Turn on a light bulb that will run on fruit energy!

To repeat such experiments at home, potatoes, especially green ones, are also suitable.

How it works? The citric acid found in lemon reacts with two different metals, which causes the ions to move in one direction, creating an electrical current. All chemical sources of electricity operate on this principle.

Summer fun

You don't have to stay indoors to do some experiments. Some experiments will work better outside, and you won't have to clean anything up after they're done. These include interesting experiments at home with air bubbles, not simple ones, but huge ones.

To make them you will need:

• 2 wooden sticks 50-100 cm long (depending on the age and height of the child);
• 2 metal screw-in ears;
• 1 metal washer;
• 3 m of cotton cord;
• bucket with water;
• any detergent - for dishes, shampoo, liquid soap.

Here's how to conduct spectacular experiments for children at home:

1. Screw metal tabs into the ends of the sticks.
2. Cut the cotton cord into two parts, 1 and 2 m long. You may not strictly adhere to these measurements, but it is important that the proportion between them is maintained at 1 to 2.
3. Place a washer on a long piece of rope so that it hangs evenly in the center, and tie both ropes to the eyes on the sticks, forming a loop.
4. Mix a small amount of detergent in a bucket of water.
5. Gently dip the loop of the sticks into the liquid and begin blowing giant bubbles. To separate them from each other, carefully bring the ends of the two sticks together.

What is the scientific component of this experiment? Explain to children that bubbles are held together by surface tension, the attractive force that holds the molecules of any liquid together. Its effect is manifested in the fact that spilled water collects into drops, which tend to take on a spherical shape, as the most compact of all existing in nature, or in the fact that water, when poured, collects into cylindrical streams. The bubble has a layer of liquid molecules on both sides sandwiched by soap molecules, which increase its surface tension when distributed over the surface of the bubble and prevent it from quickly evaporating. While the sticks are kept open, the water is held in the form of a cylinder; as soon as they are closed, it tends to a spherical shape.

These are the kinds of experiments you can do at home with children.

Experiment is one of the most informative ways of learning. Thanks to him, it is possible to obtain diverse and extensive titles about the phenomenon or system being studied. It is experiment that plays a fundamental role in physical research. Beautiful physical experiments remain in the memory of subsequent generations for a long time, and also contribute to the popularization of physical ideas among the masses. Let us present the most interesting physical experiments according to the physicists themselves from a survey by Robert Kreese and Stoney Book.

1. Experiment of Eratosthenes of Cyrene

This experiment is rightfully considered one of the most ancient to date. In the third century BC. librarian Library of Alexandria Erastophenes of Cyrene measured the radius of the Earth in an interesting way. in a day summer solstice in Siena the sun was at its zenith, as a result of which there were no shadows from objects. 5000 stadia to the north in Alexandria, at the same time, the Sun deviated from the zenith by 7 degrees. From here the librarian received information that the circumference of the Earth is 40 thousand km, and its radius is 6300 km. Erastofen obtained figures that were only 5% less than today’s, which is simply amazing for the ancient measuring instruments he used.

2. Galileo Galilei and his very first experiment

In the 17th century, Aristotle's theory was dominant and unquestioned. According to this theory, the speed at which a body falls directly depends on its weight. An example was the feather and the stone. The theory was wrong because it did not take into account air resistance.

Galileo Galilei doubted this theory and decided to conduct a series of experiments personally. He took a large cannonball and launched it from the Leaning Tower of Pisa, paired with a light musket ball. Given their close, streamlined shape, air resistance could easily be neglected and, of course, both objects landed simultaneously, refuting Aristotle's theory. believes that you need to personally go to Pisa and throw something similar in appearance and different in weight from the tower in order to feel like a great scientist.

3. Galileo Galilei's second experiment

Aristotle's second statement was that bodies under the influence of force move with constant speed. Galileo launched metal balls down an inclined plane and recorded the distance they traveled over a certain time. Then he doubled the time, but during this time the balls traveled 4 times the distance. Thus, the dependence was not linear, that is, the speed was not constant. From this Galileo concluded that motion is accelerated under the influence of force.
These two experiments served as the basis for the creation of classical mechanics.

4. Henry Cavendish's experiment

Newton is the owner of the law's formulation universal gravity, in which the gravitational constant is present. Naturally, the problem arose of finding it numerical value. But for this it would be necessary to measure the force of interaction between the bodies. But the problem is that the force of gravity is quite weak; it would be necessary to use either gigantic masses or small distances.

John Michell was able to come up with, and Cavendish to conduct in 1798, a rather interesting experiment. The measuring instrument was a torsion balance. Balls on thin ropes were attached to them on a rocker arm. Mirrors were attached to the balls. Then very large and heavy ones were brought to the small balls and the displacements along the light spots were recorded. The result of a series of experiments was the determination of the value of the gravitational constant and the mass of the Earth.

5. The experiment of Jean Bernard Leon Foucault

Thanks to the huge (67 m) pendulum, which was installed in the Paris Pantheon in 1851, Foucault experimentally proved the fact that the Earth rotates around its axis. The plane of rotation of the pendulum remains unchanged with respect to the stars, but the observer rotates with the planet. Thus, you can see how the plane of rotation of the pendulum gradually shifts to the side. This is a fairly simple and safe experiment, unlike the one we wrote about in the article

6. Isaac Newton's experiment

And again Aristotle's statement was tested. It was believed that different colors are mixtures in different proportions light and darkness. The more darkness, the closer the color is to purple and vice versa.

People have long noticed that large single crystals split light into colors. A series of experiments with prisms were carried out by the Czech naturalist Marcia English Hariot. New series Newton began in 1672.
Newton performed physical experiments in a dark room, passing a thin beam of light through a small hole in thick curtains. This beam hit the prism and was split into rainbow colors on the screen. The phenomenon was called dispersion and was later theoretically substantiated.

But Newton went further, because he was interested in the nature of light and colors. He passed rays through two prisms in series. Based on these experiments, Newton concluded that color is not a combination of light and darkness, and certainly not an attribute of an object. White light consists of all the colors that can be seen in dispersion.

7. Thomas Young's experiment

Until the 19th century, the corpuscular theory of light dominated. It was believed that light, like matter, consists of particles. Thomas Young, an English physician and physicist, conducted his experiment in 1801 to test this claim. If we assume that light has a wave theory, then the same interacting waves should be observed as when throwing two stones onto water.

To imitate stones, Jung used an opaque screen with two holes and light sources behind it. The light passed through the holes and a pattern of light and dark stripes was formed on the screen. Light stripes formed where the waves reinforced each other, and dark stripes where they extinguished each other.

8. Klaus Jonsson and his experiment

In 1961, German physicist Klaus Jonsson proved that elementary particles have a particle-wave nature. For this purpose, he conducted an experiment similar to Young’s experiment, only replacing the light rays with electron beams. As a result, it was still possible to obtain an interference pattern.

9. Robert Millikan's experiment

Even at the beginning of the nineteenth century, the idea arose that every body has an electric charge, which is discrete and determined by indivisible elementary charges. By that time, the concept of an electron as a carrier of this same charge had been introduced, but it was not possible to detect this particle experimentally and calculate its charge.
American physicist Robert Millikan managed to develop an ideal example of grace in experimental physics. He isolated charged drops of water between the plates of a capacitor. Then, using X-rays, he ionized the air between the same plates and changed the charge of the droplets.

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There are very simple experiments that children remember for the rest of their lives. The guys may not fully understand why this is all happening, but when time will pass and they find themselves in a physics or chemistry lesson, a very clear example will certainly emerge in their memory.

website I collected 7 interesting experiments that children will remember. Everything you need for these experiments is at your fingertips.

Fireproof ball

Will need: 2 balls, candle, matches, water.

Experience: Inflate a balloon and hold it over a lit candle to demonstrate to children that the fire will make the balloon burst. Then pour plain tap water into the second ball, tie it and bring it to the candle again. It turns out that with water the ball can easily withstand the flame of a candle.

Explanation: The water in the ball absorbs the heat generated by the candle. Therefore, the ball itself will not burn and, therefore, will not burst.

Pencils

You will need: plastic bag, simple pencils, water.

Experience: Fill the plastic bag halfway with water. Use a pencil to pierce the bag right through where it is filled with water.

Explanation: If you pierce a plastic bag and then pour water into it, it will pour out through the holes. But if you first fill the bag halfway with water and then pierce it with a sharp object so that the object remains stuck into the bag, then almost no water will flow out through these holes. This is due to the fact that when polyethylene breaks, its molecules are attracted closer friend to friend. In our case, the polyethylene is tightened around the pencils.

Unbreakable balloon

You will need: balloon, a wooden skewer and some dishwashing liquid.

Experience: Coat the top and bottom with the product and pierce the ball, starting from the bottom.

Explanation: The secret of this trick is simple. In order to preserve the ball, you need to pierce it at the points of least tension, and they are located at the bottom and at the top of the ball.

Cauliflower

Will need: 4 cups of water, food coloring, cabbage leaves or white flowers.

Experience: Add any color of food coloring to each glass and place one leaf or flower in the water. Leave them overnight. In the morning you will see that they have turned different colors.

Explanation: Plants absorb water and thereby nourish their flowers and leaves. This happens due to the capillary effect, in which water itself tends to fill the thin tubes inside the plants. This is how flowers, grass, and large trees feed. By sucking in tinted water, they change color.

floating egg

Will need: 2 eggs, 2 glasses of water, salt.

Experience: Carefully place the egg in a glass with a simple clean water. As expected, it will sink to the bottom (if not, the egg may be rotten and should not be returned to the refrigerator). Pour warm water into the second glass and stir 4-5 tablespoons of salt in it. For the purity of the experiment, you can wait until the water cools down. Then place the second egg in the water. It will float near the surface.

Explanation: It's all about density. The average density of an egg is much greater than that of plain water, so the egg sinks down. And the density of the salt solution is higher, and therefore the egg rises up.

Crystal lollipops

Will need: 2 cups of water, 5 cups of sugar, wooden sticks for mini kebabs, thick paper, transparent glasses, saucepan, food coloring.

Experience: In a quarter glass of water, boil sugar syrup with a couple of tablespoons of sugar. Sprinkle some sugar onto the paper. Then you need to dip the stick in the syrup and collect the sugar with it. Next, distribute them evenly on the stick.

Leave the sticks to dry overnight. In the morning, dissolve 5 cups of sugar in 2 glasses of water over a fire. You can leave the syrup to cool for 15 minutes, but it should not cool too much, otherwise the crystals will not grow. Then pour it into jars and add different food colorings. Place the prepared sticks in a jar of syrup so that they do not touch the walls and bottom of the jar; a clothespin will help with this.

Explanation: As the water cools, the solubility of sugar decreases, and it begins to precipitate and settle on the walls of the vessel and on your stick seeded with sugar grains.

Lighted match

Will be needed: Matches, flashlight.

Experience: Light a match and hold it at a distance of 10-15 centimeters from the wall. Shine a flashlight on the match and you will see that only your hand and the match itself are reflected on the wall. It would seem obvious, but I never thought about it.

Explanation: Fire does not cast shadows because it does not prevent light from passing through it.

In school physics lessons, teachers always say that physical phenomena 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, onto the pencil, not reaching its edges by 1 cm. If one row ends, wind another on top in reverse side. 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!