Easy and interesting experiments in physics. Master class “Entertaining experiments in physics using scrap materials

Can be used in physics lessons at the stages of setting the goal and objectives of the lesson, creating problem situations when studying new topic, application of new knowledge while consolidating. The presentation “Entertaining Experiments” can be used by students to prepare experiments at home, when conducting extracurricular activities in physics.

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Municipal Budgetary Educational Institution

"Gymnasium No. 7 named after Hero of Russia S.V. Vasilyev"

Scientific work

"Entertaining physical experiments

from scrap materials"

Completed: 7a grade student

Korzanov Andrey

Teacher: Balesnaya Elena Vladimirovna

Bryansk 2015

Introduction “Relevance of the topic” ……………………………3
Main part ………………………………………………...4

Organization research work………………...4
Experiments on the topic " Atmosphere pressure"……………….6
Experiments on the topic “Heat”…………………………………7
Experiments on the topic “Electricity and Magnetism”…………...7
Experiments on the topic “Light and Sound”……………………………...8

Conclusion ……………………………………………………...10
List of studied literature……………………………….12

INTRODUCTION.

Physics is not only scientific books and complex laws, not only huge laboratories. Physics is also about interesting experiments and entertaining experiences. Physics is magic tricks performed among friends, this is funny stories and funny homemade toys.

The most important thing for physical experiments you can use any available material.

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

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

When conducting experiments, you not only have to draw up a plan for its implementation, but also determine ways to obtain certain data, assemble installations yourself, and even design the necessary instruments to reproduce a particular phenomenon.

But, unfortunately, due to overload educational material Physics lessons focus on entertaining experiments insufficient attention, much attention is paid to theory and problem solving.

Therefore, it was decided to conduct research work on the topic “Entertaining experiments in physics using scrap materials.”

The objectives of the research work are as follows:

Master the methods of physical research, master the skills of correct observation and the technique of physical experiment.
Organization independent work with various literature and other sources of information, collection, analysis and synthesis of material on the topic of research work.
Teach students to use scientific knowledge to explain physical phenomena.
To instill in school students a love for physics, concentrating their attention on understanding the laws of nature, and not on memorizing them mechanically.
Replenishment of the physics classroom with homemade devices made from scrap materials.

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

Subjectivity – the chosen topic corresponds to our interests.
Objectivity – the topic we have chosen is relevant and important in scientific and practical terms.
Feasibility – the tasks and goals we set in our work are realistic and achievable.

MAIN PART.

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

Formulation of the problem.
Studying information from different sources on this issue.
Selection of research methods and practical mastery of them.
Collecting your own material – assembling available materials, conducting experiments.
Analysis and synthesis.
Formulation of conclusions.

During the research work the following were usedphysical research methods:

I. Physical experience

The experiment consisted of the following stages:

Clarification of the experimental conditions.

This stage involves familiarization with the conditions of the experiment, determination of the list of necessary available instruments and materials and safe conditions during the experiment.

Drawing up a sequence of actions.

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

Conducting the experiment.

II. Observation

When observing phenomena occurring in experience, we drew Special attention for change physical characteristics(pressure, volume, area, temperature, direction of light propagation, etc.), while we were able to detect regular relationships between various physical quantities.

III. Modeling.

Modeling is the basis of any physical research. During the experiments we simulatedisothermal compression of air, propagation of light in different environments, reflection and absorption electromagnetic waves, electrification of bodies during friction.

In total, we modeled, conducted and scientifically explained 24 entertaining physical experiments.

Based on the results of research work, it is possible to makethe following conclusions:

In various sources of information you can find and come up with many interesting physical experiments performed using available equipment.
Entertaining experiments and homemade physics devices increase the range of demonstrations of physical phenomena.
Entertaining experiments allow you to test the laws of physics and theoretical hypotheses that are of fundamental importance for science.

SUBJECT "ATMOSPHERE PRESSURE"

Experience No. 1. "The balloon won't deflate"

Materials: Three-liter glass jar with a lid, cocktail straw, rubber ball, thread, plasticine, nails.

Sequencing

Using a nail, make 2 holes in the lid of the jar - one central, the other at a short distance from the central one. Pass a straw through the central hole and seal the hole with plasticine. Tie a rubber ball to the end of the straw using a thread, close the glass jar with a lid, and the end of the straw with the ball should be inside the jar. To eliminate air movement, seal the contact area between the lid and the jar with plasticine. Blow a rubber ball through a straw and the ball will deflate. Now inflate the ball and cover the second hole in the lid with plasticine, the ball first deflates, and then stops deflating. Why?

Scientific explanation

In the first case, when the hole is open, the pressure inside the can is equal to the air pressure inside the ball, therefore, under the action of the elastic force of the stretched rubber, the ball is deflated. In the second case, when the hole is closed, air does not come out of the can; as the ball deflates, the volume of air increases, the air pressure decreases and becomes less than the air pressure inside the ball, and the deflation of the ball stops.

The following experiments were carried out on this topic:

Experience No. 2. "Pressure Equilibrium".

Experience No. 3. "The air is kicking"

Experience No. 4. "Glued Glass"

Experience No. 5. "Moving Banana"

THEME "WARMTH"

Experience No. 1. "Soap bubble"

Materials: A small medicine bottle with a stopper, a clean ballpoint pen refill or a cocktail straw, a glass of hot water, pipette, soapy water, plasticine.

Sequencing

Make a thin hole in the stopper of the medicine bottle and insert a clean ballpoint pen or a straw into it. Cover the place where the rod entered the cork with plasticine. Using a pipette, fill the rod with soapy water and place the bottle in a glass of hot water. Soap bubbles will begin to rise from the outer end of the rod. Why?

Scientific explanation

When the bottle is heated in a glass of hot water, the air inside the bottle heats up, its volume increases, and soap bubbles are inflated.

The following experiments were carried out on the topic “Heat”:

Experience No. 2. "Fireproof scarf"

Experience No. 3. "Ice doesn't melt"

SUBJECT "ELECTRICITY AND MAGNETISM"

Experience No. 1. "Current meter - multimeter"

Materials: 10 meters of insulated copper wire 24 gauge (diameter 0.5 mm, cross-section 0.2 mm 2 ), wire stripper, wide adhesive tape, sewing needle, thread, strong bar magnet, juice can, galvanic cell “D”.

Sequencing

Strip the wire from both ends of insulation. Wind the wire around the can in tight turns, leaving the ends of the wire 30 cm free. Remove the resulting coil from the can. To prevent the coil from falling apart, wrap it with adhesive tape in several places. Secure the spool vertically to the table using a large piece of tape. Magnetize the sewing needle by passing it over the magnet at least four times in one direction. Tie the needle with a thread in the middle so that the needle hangs in balance. Stick the free end of the thread inside the spool. The magnetized needle should hang quietly inside the coil. Connect the free ends of the wire to the positive and negative terminals of the galvanic cell. What happened? Now reverse the polarity. What happened?

Scientific explanation

A magnetic field arises around the current-carrying coil, and a magnetic field also arises around the magnetized needle. The magnetic field of the current coil acts on the magnetized needle and turns it. If you reverse the polarity, the direction of the current is reversed and the needle turns in the opposite direction.

In addition, the following experiments were carried out on this topic:

Experience No. 2. "Static glue."

Experience No. 3. "Fruit Battery"

Experience No. 4. "Anti-gravity discs"

THEME "LIGHT AND SOUND"

Experience No. 1. "Soap Spectrum"

Materials: Soap solution, a pipe brush (or a piece of thick wire), a deep plate, a flashlight, adhesive tape, a sheet of white paper.

Sequencing

Bend a pipe cleaner (or a piece of thick wire) so that it forms a loop. Don't forget to make a small handle to make it easier to hold. Pour the soap solution into a plate. Dip the loop into the soapy water and let it soak thoroughly in the soapy water. After a few minutes, carefully remove it. What do you see? Are colors visible? Attach a sheet of white paper to the wall using masking tape. Turn off the lights in the room. Turn on the flashlight and point its beam at the loop with soap suds. Position the flashlight so that the loop casts a shadow on the paper. Describe the full shadow.

Scientific explanation

White light is a complex light, it consists of 7 colors - red, orange, yellow, green, blue, indigo, violet. This phenomenon is called light interference. When passing through a soap film, white light breaks up into individual colors, the different light waves on the screen form a rainbow pattern, which is called a continuous spectrum.

On the topic “Light and Sound” the following experiments were carried out and described:

Experience No. 2. "On the edge of the abyss".

Experience No. 3.

Experience No. 4. "Just for fun"

Experience No. 5. "Remote control"

"Copier" Experience No. 6.

"Appearing Out of Nowhere"

Experience No. 7. "Colored spinning top" Experience No. 8.

"Jumping Grains" Experience No. 9.

"Visual Sound"

Experience No. 10. "Blowing out the sound" Experience No. 11.

"Intercom" Experiment No. 12.

"Crowing Glass"

CONCLUSION Analyzing the results of entertaining experiments, we were convinced that school knowledge

quite applicable to solving practical issues.

Using experiments, observations and measurements, the relationships between various physical quantities were studied

Volume and pressure of gases

Pressure and temperature of gases Number of turns and size magnetic field

around the current coil

By gravity and atmospheric pressure

The direction of light propagation and the properties of a transparent medium. All phenomena observed during entertaining experiments have scientific explanation

, for this we used the fundamental laws of physics and the properties of the matter around us - Newton’s II law, the law of conservation of energy, the law of rectilinearity of light propagation, reflection, refraction, dispersion and interference of light, reflection and absorption of electromagnetic waves.

In accordance with the task, all experiments were carried out using only cheap, small-sized improvised materials; during their implementation, 8 home-made devices were made, including a magnetic needle, a copier, a fruit battery, a current meter - a multimeter, an intercom; the experiments were safe, visual, simple in design.

* LIST OF REFERENCES STUDYED

- Fields are required.

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

What can experiments teach children?

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

So let's make our children proficient!

1. Create a new color

This experiment will be useful for preschoolers and primary schoolchildren. To conduct the experiment we will need:

flashlight;
red, blue and yellow cellophane;
ribbon;
white wall.

We conduct the experiment near a white wall:

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

2. Black color and Sunbeam: explosive combination

To carry out the experiment you will need:

1 clear and 1 black balloon IR;
magnifying glass;
Sun Ray.

This experience will require skill, but you can do it.

First you need to inflate a transparent balloon. Hold it tightly, but do not tie the end.
Now use the blunt end of a pencil to push the black balloon half transparent inside.
Inflate the black balloon inside the clear one until it fills about half the volume.
Tie the end of the black ball and push it into the middle of the clear ball.
Inflate the transparent balloon a little more and tie the end.
Position the magnifying glass so that the sun's ray hits the black ball.
After a few minutes, the black ball will burst inside the transparent one.

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

3. Lazy ball

The next experiment is a real show, but you will need to practice to carry it out. The school gives an explanation for this phenomenon in the 7th grade, but in practice this can be done even in preschool age. Prepare the following items:

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

How to conduct this experiment?

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

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

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

4. Raw or cooked?

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

· cooled hard-boiled egg;

· 2 raw eggs;

Invite a group of children to distinguish a boiled egg from a raw one. However, eggs cannot be broken. Say that you can do it without fail.

Roll both eggs on the table.
An egg that spins faster and with uniform speed, - boiled.
To prove your point, crack another egg into a bowl.
Take a second raw egg and a paper napkin.
Ask a member of the audience to make the egg stand on the blunt end. No one can do this except you, since only you know the secret.
Just vigorously shake the egg up and down for half a minute, then easily place it on a napkin.

Why do eggs behave differently?

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

5. “Golden” mean

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

Raise the stick to waist level.
Lay her down on 2 index fingers, keeping them at a distance of 60 cm.
Move your fingers closer friend to a friend and make sure that the stick does not lose its balance.
When your fingers come together and the stick is parallel to the floor, you have reached your goal.
Place the stick on the table, keeping your finger on the desired mark. Use a ruler to make sure you have completed the task accurately.

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

6. Zero gravity in a jar

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

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

How to conduct the experiment?

Thread the needles and tie the ends with two knots.
Tape the knots to the bottom of the jar, leaving about 1 inch (2.5 cm) to the edge.
From the inside of the lid, glue the tape in the form of a loop, with the sticky side facing out.
Place the lid on the table and glue a magnet to the hinge. Turn the jar over and screw on the lid. The needles will hang down and be drawn towards the magnet.
When you turn the jar upside down, the needles will still be drawn to the magnet. You may need to lengthen the threads if the magnet does not hold the needles upright.
Now unscrew the lid and place it on the table. You are ready to perform the experiment in front of an audience. As soon as you screw on the lid, the needles from the bottom of the jar will shoot up.

Tell your child that a magnet attracts iron, cobalt and nickel, so iron needles are susceptible to its influence.

7. “+” and “-”: beneficial attraction

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

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

Experiment stages:

Place a paper towel on the floor and sprinkle the salt and pepper mixture on it.
Ask your child: how to separate salt from pepper now?
Rub the inflated balloon on a woolen item.
Season it with salt and pepper.
The salt will remain in place, and the pepper will be magnetized to the ball.

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

Experiences at home are valuable life experiences

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

trust you;
see the amazing in everyday life;
It’s exciting to learn the laws of the world around you;
develop diversified;
learn with interest and desire.

We remind you once again that developing a child is simple and you don’t need a lot of money and time. See you soon!

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

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

1. Experiment of Eratosthenes of Cyrene

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

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

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

2. Galileo Galilei's experiment

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

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

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

3. Another Galileo Galilei experiment

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

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

4. Henry Cavendish's experiment

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

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

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

5. Jean Bernard Foucault's experiment

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

6. Isaac Newton's experiment

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

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

However, before Newton, such observations were not subjected to serious analysis, and the conclusions drawn on their basis were not cross-checked by additional experiments. Both Hariot and Marzi remained followers of Aristotle, who argued that differences in color are determined by differences in the amount of darkness “mixed” with white light. Purple, according to Aristotle, arises with the greatest addition of darkness to light, and red with the least. Newton carried out additional experiments with crossed prisms, when light passed through one prism then passes through another. Based on the totality of his experiments, he concluded that “no color arises from white and black mixed together, except the intermediate dark ones; the amount of light does not change the appearance of the color.” He showed that white light should be considered as a compound. The main colors are from purple to red. This Newton experiment serves wonderful example as different people, observing the same phenomenon, interpret it in different ways, and only those who question their interpretation and carry out additional experiments come to the correct conclusions.

7. Thomas Young's experiment

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

8. Klaus Jonsson's experiment

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

9. Robert Millikan's experiment

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

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

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

10. Ernst Rutherford's experiment

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

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

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 New Year, but also 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 into the bottle several times hot water 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 medium is formed in the bottle low blood pressure, where the water is directed to restore balance, because atmospheric pressure presses on the water 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.

Empty open glass bottle leave in 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 maximum speed flow 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 friends by clicking on the buttons social networks so that other mothers can please their babies with interesting experiments!

BOU "Koskovskaya Secondary School"

Kichmengsko-Gorodetsky municipal district

Vologda region

Educational project

"Physical experiment at home"

Completed:

7th grade students

Koptyaev Artem

Alekseevskaya Ksenia

Alekseevskaya Tanya

Supervisor:

Korovkin I.N.

March-April-2016.

Content

Introduction

There is nothing better in life than your own experience.

Scott W.

At school and at home we became acquainted with many physical phenomena and we wanted to make homemade devices, equipment and conduct experiments. All the experiments we conduct allow us to gain deeper knowledge the world and in particular physics. We describe the process of manufacturing equipment for the experiment, the principle of operation and the physical law or phenomenon demonstrated by this device. The experiments carried out interested students from other classes.

Target: make a device from available means to demonstrate a physical phenomenon and use it to talk about physical phenomenon.

Hypothesis: manufactured devices and demonstrations will help to understand physics more deeply.

Tasks:

Study the literature on conducting experiments yourself.

Watch a video demonstrating the experiments

Make equipment for experiments

Give a demonstration

Describe the physical phenomenon being demonstrated

Improve the material resources of the physicist's office.

EXPERIMENT 1. Fountain model

Target : show the simplest model fountain.

Equipment : plastic bottle, dropper tubes, clamp, balloon, cuvette.

Ready product

Progress of the experiment:

We will make 2 holes in the cork. Insert the tubes and attach a ball to the end of one.

Fill the balloon with air and close it with a clamp.

Pour water into a bottle and place it in a cuvette.

Let's watch the flow of water.

Result: We observe the formation of a water fountain.

Analysis: works on bottled water compressed air, located in the ball. The more air in the ball, the higher the fountain will be.

EXPERIENCE 2. Carthusian diver

(Pascal's law and Archimedes' force.)

Target: demonstrate Pascal's law and Archimedes' force.

Equipment: plastic bottle,

pipette (vessel closed at one end)

Ready product

Progress of the experiment:

Take plastic bottle capacity 1.5-2 liters.

Take a small vessel (pipette) and load it with copper wire.

Fill the bottle with water.

Press down on the top of the bottle with your hands.

Observe the phenomenon.

Result : we observe the pipette sinking and rising when pressing on the plastic bottle..

Analysis : The force compresses the air above the water, the pressure is transferred to the water.

According to Pascal's law, pressure compresses the air in the pipette. As a result, Archimedes' power decreases. The body is drowning. We stop the compression. The body floats up.

EXPERIMENT 3. Pascal's law and communicating vessels.

Target: demonstrate the operation of Pascal's law in hydraulic machines.

Equipment: two syringes of different volumes and a plastic tube from a dropper.

Ready product.

Progress of the experiment:

1.Take two syringes different sizes and connect with a tube from an IV.

2.Fill with incompressible liquid (water or oil)

3.Press the plunger of the smaller syringe. Observe the movement of the plunger of the larger syringe.

4. Press down on the plunger of the larger syringe. Observe the movement of the plunger of the smaller syringe.

Result : We fix the difference in the applied forces.

Analysis : According to Pascal's law, the pressure created by the pistons is the same. Consequently: how many times larger is the piston, the greater is the force it creates.

EXPERIMENT 4. Dry from the water.

Target : show the expansion of heated air and compression of cold air..

Equipment : glass, plate with water, candle, cork.

Ready product.

Progress of the experiment:

1. pour water into a plate and place a coin on the bottom and a float on the water.

2. We invite the audience to take out the coin without getting their hand wet.

3.light the candle and place it in the water.

4. Cover with a heated glass.

Result: We observe the movement of water into the glass..

Analysis: When the air is heated, it expands. When the candle goes out. The air cools and its pressure decreases. Atmospheric pressure will push the water under the glass.

EXPERIENCE 5. Inertia.

Target : show the manifestation of inertia.

Equipment : Wide-neck bottle, cardboard ring, coins.

Ready product.

Progress of the experiment:

1. Place a paper ring on the neck of the bottle.

2. Place coins on the ring.

3. knock out the ring with a sharp blow of a ruler

Result: We watch the coins fall into the bottle.

Analysis: inertia is the ability of a body to maintain its speed. When you hit the ring, the coins do not have time to change speed and fall into the bottle.

EXPERIENCE 6. Upside down.

Target : Show the behavior of a liquid in a rotating bottle.

Equipment : Wide-neck bottle and rope.

Ready product.

Progress of the experiment:

1. We tie a rope to the neck of the bottle.

2. pour water.

3.rotate the bottle over your head.

Result: water does not pour out.

Analysis: At the top point, the water is acted upon by gravity and centrifugal force. If centrifugal force more power gravity, the water will not spill out.

EXPERIMENT 7. Non-Newtonian liquid.

Target : Show the behavior of a non-Newtonian fluid.

Equipment : bowl.starch. water.

Ready product.

Progress of the experiment:

1. In a bowl, dilute starch and water in equal proportions.

2. demonstrate the unusual properties of the liquid

Result: substance has properties solid and liquids.

Analysis: with a sharp impact, the properties of a solid appear, and with a slow impact, the properties of a liquid appear.

Conclusion

As a result of our work, we:

conducted experiments proving the existence of atmospheric pressure;

created home-made devices demonstrating the dependence of liquid pressure on the height of the liquid column, Pascal’s law.

We enjoyed studying pressure, making homemade devices, and conducting experiments. But there is a lot of interesting things in the world that you can still learn, so in the future:

We will continue to study this interesting science

We hope that our classmates will be interested in this problem, and we will try to help them.

In the future we will conduct new experiments.

Conclusion

It is interesting to observe the experiment conducted by the teacher. Carrying it out yourself is doubly interesting.

And conducting an experiment with a device made and designed with your own hands 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.

Carrying out these experiments is not difficult and interesting. They are safe, simple and useful. New research is ahead!

Literature

Physics evenings at high school/ Comp. EM. Braverman. M.: Education, 1969.

Extracurricular work in physics / Ed. O.F. Kabardina. M.: Education, 1983.

Galperstein L. Entertaining physics. M.: ROSMEN, 2000.

GorevL.A. Entertaining experiments in physics. M.: Education, 1985.

Goryachkin E.N. Methodology and technique of physical experiment. M.: Enlightenment. 1984

Mayorov A.N. Physics for the curious, or what you won't learn about in class. Yaroslavl: Academy of Development, Academy and K, 1999.

Makeeva G.P., Tsedrik M.S. Physical paradoxes and interesting questions. Minsk: Narodnaya Asveta, 1981.

Nikitin Yu.Z. Time for fun. M.: Young Guard, 1980.

Experiments in a home laboratory // Quantum. 1980. No. 4.

Perelman Ya.I. Entertaining mechanics. Do you know physics? M.: VAP, 1994.