We make a paper ball in different techniques. Project on the topic: "Entertaining experiments in physics"

The brilliant scientist Blaise Pascal made many discoveries in physics. The most famous law, named after him, on the transfer of pressure in liquids and gases.

Pascal confirmed all his research in physics with experiments.

Pascal's ball

So Pascal's law says: The pressure exerted on a liquid or gas is transmitted uniformly to any point and in any direction.

This law is easily confirmed with the help of an apparatus called Pascal's Ball.

Pascal's ball is a hollow ball with many small holes. The ball is connected to a cylinder in which a piston is inserted.

During the experiment, the ball is filled with water and with the help of a piston the pressure inside it is increased. Water begins to pour out of absolutely all the holes in the ball. This proves that the pressure that the piston creates on the surface of the liquid is transmitted by the liquid equally in all directions.

If the ball is filled with smoke, then in the same way the smoke will come out of all the holes of the ball with the pressure of the piston.

Pascal's law can also be confirmed using the simplest device, made independently from ordinary plastic bottle with screw cap. Poke holes in the bottom and sides. Pour in water and close the lid. Water flows equally from all holes, which confirms Pascal's law.

Pascal hydrostatic balance

A liquid, like any body on Earth, is affected by the force of gravity. Each layer of liquid creates pressure on other layers. According to Pascal's law, this pressure is transmitted in any direction. This means that pressure exists inside the liquid as well.

This pressure is determined by the formula p=gρh, where p is the fluid pressure at depth h is the height of the liquid column, g is the acceleration free fall, ρ is the liquid density.

That is, the pressure of the liquid depends on the height of the column. Therefore, the liquid presses on the bottom of the vessel with the same force. This force is called hydrostatic force.

The device proposed by Pascal for measuring hydrostatic force is called hydrostatic Pascal balance. The device is a stand on which it is possible to fix vessels that do not have a bottom. All vessels have a different shape. The bottom of the vessel is a round plate suspended from the balance beam, which is pressed tightly from below. If a liquid is poured into the vessel, a pressure force begins to act on the plate. And if this force is greater than the weight of the weight, which stands on the other pan of the balance, the plate comes off the vessel.

Experiments were carried out with vessels various shapes. But the bottom of all vessels had the same area.

In a cylindrical vessel, the plate was torn off from the bottom when the weight of the liquid was compared with the weight of the weight. In vessels having a different shape, the bottom was opened at the same height of the water column. But for a vessel with a shape expanding upwards, this happened at a weight greater than the weight of the weight, and for a vessel tapering upwards, the weight of water was less weight weights. From this experience, we can conclude that with the appropriate shape of the vessel, it is possible to obtain huge pressure forces on the bottom even with the help of a very small amount of water.

This was proved by another experiment of Pascal, which he carried out in 1648.

A narrow long vertical tube was inserted into a tightly sealed barrel of water. Climbing up to the balcony of the second floor, Pascal poured several mugs of water into the pipe. Since the tube was very thin, the water in it rose to a great height. The force of pressure on the walls and bottom of the barrel was so great that the barrel cracked.

The same amount of water exerts different pressure on the bottom if it is in vessels different shapes. Moreover, in narrow vessels, much more pressure can be created than in wide ones.

Ministry of General and vocational education

Sverdlovsk region

General education department

GBOU SPO "Krasnoufimsk Pedagogical College"

Educational area"Natural Science"

PROJECT

in physics in grade 8

Entertaining experiences in physics

Performed:

Gontsova E. A.

8th grade student

Supervisor:

Zueva G.R.

Physics teacher

Krasnoufimsk

Introduction ……………………………………………………………………...………...3

A bit of history ………………………………………….…………………….…..4

Practical part……………………………………………………………………… 5

Conclusion………………………………………………………………….………....14

List of sources used……………………………….………………..15

Applications………………………………………………………………………………16

Section 1

Introduction

“One experience is worth a thousand words.”
(Arabic proverb)

Physical experiments In an entertaining way, they introduce students to the various applications of the laws of physics. Experiments can be used in the classroom to draw students' attention to the phenomenon being studied, with repetition and consolidation. educational material, at physical evenings. Entertaining experiences deepen and expand the knowledge of students, contribute to the development logical thinking instill interest in the subject.

The role of experience in the science of physics

That physics is a young science
Can't say for sure here.
And in ancient times knowing science,
Always strive to reach it.

The purpose of teaching physics is specific,
To be able to apply all knowledge in practice.
And it is important to remember - the role of the experiment
Must be in the first place.

Know how to plan and execute experiments.
Analyze and bring to life.
Build a model, put forward a hypothesis,
Strive to reach new heights.

The laws of physics are based on facts established by experience. Moreover, the interpretation of the same facts often changes in the course of the historical development of physics. Facts accumulate as a result of observations. But at the same time, they cannot be limited only to them. This is only the first step towards knowledge. Next comes the experiment, the development of concepts that allow qualitative characteristics. In order to draw general conclusions from observations, to find out the causes of phenomena, it is necessary to establish quantitative relationships between quantities. If such a dependence is obtained, then a physical law is found. If a physical law is found, then there is no need to set up an experiment in each individual case, it is enough to perform the appropriate calculations. Having studied experimentally the quantitative relationships between the quantities, it is possible to identify patterns. Based on these regularities, a general theory of phenomena is developed.

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

Section 2

A bit of history

An Arabic proverb says: "One experience is worth a thousand words." Based on this very fair statement, we bring to your attention a variety of experiments in physics for children under 12 years old. The experiments we offer will help you to see, remember and, most importantly, understand the essence of the physical laws and principles by which our world is arranged in a more visual form. After all, theory, as you know, without practice is dead, and without practical confirmation, everything physical formulas and theorems can be attributed to the realm of assumptions, conjectures and theoretical speculations. Theory gives knowledge, while practice gives confidence in this knowledge, and this confidence, in turn, is the basis that is the basis of world perception.

From infancy, a person cognizes the reality surrounding him exclusively in direct interaction with it. Over time, practical experience replaces words. Thus, a person, relying more and more on words, moves away from reality.

Experiments in physics are an opportunity for a person to more thoroughly understand the structure of his world.

Alone or together with friends, and sometimes with the help of parents, by performing these simple but exciting experiments, children will be able to take their first steps in physics. The experiments are accompanied by clear instructions with pictures. All submitted physical experiments safe, do not require special equipment and materials.

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

Name of experience

Instruments and materials necessary for the experiment

Stages of the experiment

Explanation of experience

Section 3

Practical part

Experience number 1 Spinning snake

Devices and materials: thick paper, spirit lamp, matches, scissors.

Stages of the experiment

Cut a spiral out of thick paper, stretch it a little and put it on the end of a curved wire or rope.

Hold this spiral over the spirit lamp in an updraft of air, the snake will rotate.

Explanation of experience

The snake rotates because there is an expansion of air under the action of heat and the transformation of warm energy into motion.

Experience #2 Fountain

Devices and materials: round bottom flask, rubber stopper with a glass tube, Komovsky vacuum pump, a vessel with water.

Stages of the experiment

Take a round-bottom flask (large capacity is better). Insert a rubber stopper tightly into its neck with a small glass tube passed through it. (The end of the tube in the flask should have a hole with a diameter of 1-2 mm). Put a rubber clamp on the glass tube, and a screw clamp on it.

Before the experiment, attach the flask to a Komovsky pump (or hand pump Shints) and pump out the air. Quickly clamp the rubber tube.

Quickly clamp the rubber tube. Disconnect the flask from the pump and lower the end of the tube into glass jar with colored liquid. Remove the clamp - a fountain is observed.

Explanation of experience

The fountain is explained by atmospheric pressure and rarefaction obtained in the flask.

Experience number 3 "Without wet hands"

Devices and materials: plate or saucer, coin, glass, spirit lamp, matches.

Stages of the experiment

Put a coin on the bottom of a plate or saucer and pour some water. How to get a coin without even getting your fingertips wet?

Light the paper, put it into the glass for a while. Turn the heated glass upside down and place on a saucer next to the coin.

Explanation of experience

As the air in the glass is heated, its pressure will increase and some of the air will escape. The remaining air will cool after a while, the pressure will decrease. Under the action of atmospheric pressure, water will enter the glass, freeing the coin.

Experience No. 4 Pascal's Ball

Devices and materials: Pascal's ball, colored water, large glass jar.

Stages of the experiment

Pour colored water into a glass vessel, draw air into the pascal ball, lower the ball into the water, push the piston into the vessel, observe bubbles around the entire perimeter.

We draw water into the pascal ball, take it out of the water, apply force to the handle, observe the outflow of liquid from the holes in the ball, pay attention to the uniform outflow of liquid in all directions: trickles of water from all holes in the ball.

Explanation of experience

Pascal's law states that a liquid or gas transmits the pressure produced on them unchanged to all points. The brilliant scientist Blaise Pascal made many discoveries in physics. The most famous law, named after him, on the transfer of pressure in liquids and gases.

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

Experience No. 5 Electrophore machine (conversion of mechanical energy)

Devices and materials: Electrophore machine.

Stages of the experiment

We take an electrophore machine, we begin to turn the handle, the disks begin to rotate.

Both discs have conductive segments that are isolated from each other. Two plates on both sides of the disks together form one capacitor each. Because of this, it is sometimes also called a capacitor machine. On each disk there is also a neutralizer, which removes the charge with brushes from two opposite segments of the disk to the ground. From the left and right side disks are collectors. They receive generated charges removed by combs from the edges of both the front and rear discs. In most cases, the charges are collected in capacitors, such as the Leyden jar, to produce stronger sparks. Before starting operation, it is necessary to electrify the frames with opposite charges (for example, p +, and p -). These frames (strips), in accordance with the phenomenon of induction, will act on the rotating disk B (Figure 2), and through it on the combs O and O, while p, having a positive charge, will cause, through the influence, the appearance of a negative charge in part m of the disk B and will attract the same charge from comb O, which will be deposited in part m of disk B.

Explanation of experience

Current sources are different, but in each of them work is done to separate positively and negatively charged particles. Separated particles accumulate at the poles of the current source. One pole of the current source is charged - positively, the other - negatively. If the source poles are connected by a conductor, then under the action electric field free charged particles in the conductor will begin to move in a certain direction, there is electricity. In current sources, in the process of separating charged particles, a mechanical, internal, or some other kind of transformation into electrical occurs. In the electrophore machine electrical energy mechanical energy is converted.

Section 6

Appendix

Project passport

Project name: Entertaining experiments in physics.

Project leader: Zueva Guzel Rashitovna (physics teacher).

Purpose: to develop cognitive interest, interest in physics; develop competent monologue speech using physical terms, develop attention, observation, the ability to apply knowledge in a new situation.

1. Analyze the scientific literature on experiments in physics

2. Study safety precautions when conducting experiments.

3. Study the stages of conducting experiments

4. Conduct experiments

5. Develop videos with fun experiences

The presentation and video materials can be used in physics lessons to attract students' attention to the phenomenon under study, while repeating and consolidating educational material, at physical evenings. Physical experiments in an entertaining way introduce students to the various applications of the laws of physics. Entertaining experiments deepen and expand students' knowledge, contribute to the development of logical thinking, instill interest in the subject.

Product structure: Presentation and video materials.

Product size: 58.7MB.

Material: electronic document ( Microsoft File PowerPoint ) (Media file).

Storage conditions: Presentation and video materials should be stored on electronic media, protected from dust, moisture and sunlight. Most often, electronic media with information are flash cards, which must be stored in safe places from damage due to their fragility, in order to avoid loss of information.

Customer OO GBOU SPO SO "Krasnoufimsk Pedagogical College".

State educational institution of higher

vocational education

"Birsk State Social-Pedagogical Academy"

Department of General Physics and Methods of Teaching Physics

INSTRUCTIONS

to laboratory work No. 8

Birsk - 2008

Laboratory work number 8.

Pressure of solids, liquids and gases

Work instructions

Objective: Learn to develop experimental setups, conduct experiments that demonstrate the basic elements of knowledge in the topic.

Exercise 1. Study the topic “Pressure of solids, liquids and gases” from a school textbook (Grade 7). Repeat the basic knowledge that should be learned by students in this topic and write down in a notebook the wording of the elements of knowledge related to the system of a demonstration experiment in this topic (see task 3).

Task 2. Study the following devices according to the descriptions and instructions:

A device for demonstrating pressure in a liquid;

Pascal's ball

Bucket of Archimedes;

Manometer metal demonstration;

Manometer open demonstration;

Air pump manual;

Komovsky pump;

Plate to the vacuum pump;

Aneroid barometer

Task 3. Develop schematic diagrams and mount experimental setups using available instruments for the following experiments:

pressure in a liquid.

Measurement of pressure in a liquid.

Pascal's law

Atmosphere pressure.

The device and operation of a metal pressure gauge

The action of an aneroid barometer

Archimedean strength.

Task 4. Prepare to conduct experiments with the collected EC according to the following plan:

Purpose of the experiment;

Experiment method;

Design and construction of the EU (or description of the finished EU);

Experiment plan;

Analysis of the obtained results;

Conclusion from experience;

Empirical conclusion;

Theory of experiment.

Task 5. Prepare a written lab report including:

Job title; Objective;

Task 1 results;

Task 2 results.

Description of experiments according to the plan specified in task 4 with ES drawings.

Descriptions of fixtures used in the topic

Pascal's ball designed to demonstrate the transfer of pressure produced on a liquid in a closed vessel, and to demonstrate the rise of a liquid behind a piston under the influence of atmospheric pressure.

The device consists of a glass cylinder, a piston with a rod, a handle and a hollow plastic ball with several holes.

The ball is connected to the cylinder by means of a thread and can be easily separated from it.

The principle of operation of the device is based on the dependence of the rate of liquid outflow from the holes on the pressure under which the liquid is in the vessel.

If there are several identical holes in the vessel, from which liquid flows out at the same speed, then we can say that the liquid at these holes is under the same pressure.

After the demonstration, remove the water from the piston, unscrew the ball and dry the device.

Bucket of Archimedes serves to demonstrate the phenomenon of expulsion by a liquid of a body immersed in it and to measure the buoyancy force.

The device is equipped on top with a bail for hanging to a dynamometer, and on the bottom with a ring for hanging a piston.

The internal dimensions of the bucket correspond to the external dimensions of the piston. The piston has a hole in the upper part for hanging from a bucket with a wire. Inside, the piston is filled with a mixture of sand and alabaster in such a way that its density is relatively small in order to obtain well-marked deviations of the dynamometer pointer when the piston is immersed in water.

The upper end of the dynamometer spring is put on the hook of the bracket, and a rod with a disk-shaped pointer and a hook at the bottom is suspended from the lower end for hanging a bucket.

The spring can be easily removed and replaced with a more or less elastic one, which is sometimes necessary when using the dynamometer for other purposes. In these cases, the spring can be made by yourself.

Reading of indications is made according to the mobile index that is on a plate which in turn can move on a bracket. The plate has folds for attaching paper, which is necessary when you need to calibrate the dynamometer.

After using the device, the piston is removed from the bucket and wiped dry.

Instrument for demonstrating pressure in a liquid designed to study the pressure inside the liquid, while studying Pascal's law and allows you to demonstrate the change in pressure with the depth of immersion and the independence of pressure at a given depth from the orientation of the sensor.

The device consists of a pressure sensor, which is a box, one wall of which is made of a thin rubber film. The sensor has a branch pipe for connecting the cavity using an elastic tube with an open liquid manometer. The sensor is mounted on a rod and with the help of another rod with a hook (or a belt drive) can be rotated in any direction. The rod has a movable spring clip for mounting the device on the vessel wall.

Demonstration metal manometer(Fig. 9) is designed to study the device and principle of operation of a metal pressure gauge and to measure pressure greater than atmospheric pressure.

The measurement limit is 6 * 10 5 Pa (6 atm.), The price of division of the instrument scale is 5 * 10 4 Pa ​​(0.5 atm.). The manometer is mounted on a vertical stand with a tripod. The pointer of the device can be removed and installed anywhere on the scale. The manometer has two taps. The device is very sensitive to various deformations.

Technical pressure gauge(Fig. 10) is designed to measure pressures up to 1.5 * 10 5 Pa. A pressure gauge can be used to measure pressure both above and below atmospheric pressure. The pressure gauge is mounted on a stand with a tripod; it has two taps for connecting to other appliances.

Manometer open demonstration(Fig. 11) is designed to study the principle of operation of the pressure gauge and to measure pressure up to 4000 Pa (400 mm w.c.).

The U-shaped tube of the device is mounted on a rack with a stand. On the scale of the device (zero in the middle) centimeter divisions are applied. On the reverse side of the scale (in its upper part), a glass tee is fixed, which is connected to the pressure gauge on one side, and to the installation on the other, and a rubber tube with a clamp is put on the middle process, which allows you to compare the liquid levels in both knees without turning off the devices.

Manual air pump(Fig. 12) makes it possible to obtain a rarefaction of up to 5 * 10 3 Pa (0.05 atm) and injection of up to 4 * 10 5 Pa (4 atm). The straight pipe works for vacuum, and the side pipe works for injection. A rubber hose is put on the nozzles.

The operation of the pump is carried out with the reciprocating movement of the piston, with which the handle is connected.

For a tighter fit to the walls of the cylinder, the piston must be lubricated from time to time with petroleum jelly or grease.

If the caps, which play the role of valves, lose their elasticity, then they can be made from a rubber tube with a diameter of 7 mm and a length of 2.5-3 cm. A slit is cut along the tube with a razor, one end of the tube is closed with a cork and tightly tied with a thread.

Vacuum pump Komovsky(Fig. 13) allows you to get a rarefaction up to injection up to 4 * 10 5 Pa. The pump is mounted in a housing mounted on a stand. A flywheel with a handle is displayed on the side, there are two nipples on top, on which a thick-walled rubber hose can be put on. One nipple is for injection, the other is for dilution.

For normal operation of the pump, it is necessary to rotate the handle at a speed of 120 -150 rpm.

plate to vacuum pump (Fig. 14) serves to demonstrate experiments at reduced atmospheric pressure.

The plate consists of a massive cast iron disk with a connecting channel, a lockable stopcock and a mercury manometer. On the side of the disk, two outer clamps are mounted, connected to the clamps under the bell. A vacuum is created under the glass bell. A circle of thin rubber is laid between its polished sides and the disc, which prevents air from penetrating under the bell.

The vacuum pump plate together with the pump can be used in many experiments illustrating the properties of gases, vapors and liquids. For example, you can demonstrate the boiling of a liquid under reduced pressure, the expansion of a rubber chamber under reduced pressure, etc.

Aneroid barometer(Fig. 15) serves to demonstrate the operation of a metal barometer and measure normal atmospheric pressure. To check the aneroid barometer with the mercury one, there is a small hole in the case that opens access to the corrector.

To make a ball out of paper, you can use one of the ready-made patterns or turn to the papier-mâché technique. First, let's analyze the method using ready-made templates.

Ball glued according to the finished scheme

For this project you will need the following:

• Paper
• Scissors
• Scheme of the ball (it can be)

Print and cut out the diagram along the contour lines, including labels for gluing its fragments. Glue all the strips one by one, moving clockwise. When the body of the ball is ready, let it dry, then apply glue to the round "cap" and gently press it to the ball.

As you can see, here gluing occurs in parallel on both sides. Each template from this file must be printed 6 times, cut out and glued together.

Ball of paper strips

Necessary tools and materials:

• Ruler and pencil
• Scissors
• Heavy paper
• Glue or double sided tape

Procedure:

1. Draw and cut the paper into equal strips. Remember that the width of the stripes determines the density of the figure, and the length determines its diameter.

For each ball you will need 6 strips of paper.

2. Roll one of the strips into a ring and glue the ends together. Set the ring aside, you'll need it later.

3. Bind the remaining 5 strips like this:

4. Next, place the ring in the center of the weave and tuck every second strip inside it, starting with any of those that, when unfolded, were under the adjacent one. For example, in our picture, this is the top green stripe.

Hold the ring in the middle of the workpiece so that the ball is even.

5. Then crosswise, alternating the top and bottom, weave the strips of paper over the ring, and glue the ends of the same color.

If you do everything right, the finished ball will consist of rings intertwined in the form of triangles and pentagons flowing into each other.

And once again this video lesson:

Papier-mâché paper ball

When making a papier-mâché figure, you cannot do without a special adhesive solution, which is made from white flour and cold water in a ratio of 1:5. In addition, to avoid the appearance of mold on finished goods, you can add a little salt to the solution.

Mix a glass of flour and a glass of water in a small bowl, stir thoroughly and place over medium heat. Add 4 more glasses of water. Whisking constantly, bring the mixture to a jelly-like consistency (this process will take approximately 3-5 minutes). Then remove the bowl from the stove and let the contents cool to room temperature.

While the glue is cooling, prepare the following materials and tools:

• Balloon
• Paper cut into strips (newspaper, paper towels, or thick napkins work best)
• Brush for applying glue
• Gloves

Operating procedure:

1. First of all, you need to make the basis for the ball. inflate balloon so that it becomes rounded, but at the same time remains soft enough. Pasting it with strips of paper, you can give it the correct spherical shape later.

2. Completely immerse the strip of paper in the cooled glue, remove excess solution with your fingers, and stick the paper on the ball. Repeat this procedure, evenly distributing the strips over the surface of the base, until you cover it entirely in 1 or 2 layers.

When the glue begins to thicken, adjust the shape of the figure by slightly squeezing it from all sides.

3. Put the figure on a plastic cup and leave it overnight to dry.

4. When the workpiece is dry, cover it with another 1-2 layers of paper and leave to dry for some more time.

Experience #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 one above the other in five floors. However, it will be more convenient for us to take not a glass, but a narrow glass expanding towards the top.

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

Picture 1

So we got four floors of liquids in one glass. All different color and different densities.

Explanation of experience

The liquids in the groceries were arranged in the following order: tinted water, red wine, sunflower oil, tinted alcohol. The heaviest are at the bottom, the lightest are at the top. Salt water has the highest density, tinted alcohol has the smallest.

Experience #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.

Figure 2

1. Weight the end of the candle with a nail.
2. Calculate the size of the nail so that the candle is completely immersed in water, only the wick and the very tip of the paraffin should protrude above the water.
3. Light the fuse.

Explanation of experience

Let me, they will tell you, because in a minute the candle will burn down to water and go out!

That's just the point, - you will answer, - that the candle is getting shorter every minute. And if it's shorter, it's easier. If it's easier, then it will float.

And, true, the candle will gradually float up, and the paraffin cooled by water at the edge of the candle will melt more slowly than the paraffin surrounding the wick. Therefore, a rather deep funnel is formed around the wick. This emptiness, in turn, lightens the candle, and that is why our candle will burn out to the end.

Experience No. 3 Candle behind a bottle

Devices and materials: candle, bottle, matches

Stages of the experiment

1. Put a lit candle behind the bottle, and stand yourself so that your face is 20-30 cm away from the bottle.
2. It is worth now to blow, and the candle will go out, as if there is no barrier between you and the candle.

Figure 3

Explanation of experience

The candle goes out because the bottle is “flown around” with air: the jet 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 flame of a candle stands.

Experience number 4 Spinning snake

Devices and materials: thick paper, candle, scissors.

Stages of the experiment

1. Cut a spiral out of thick paper, stretch it a little and put it on the end of the bent wire.
2. Holding this coil over the candle in an updraft of air will cause the snake to spin.

Explanation of experience

The snake rotates because there is an expansion of air under the action of heat and the transformation of warm energy into motion.

Figure 4

Experience No. 5 Eruption of Vesuvius

Devices and materials: glass vessel, vial, cork, alcohol ink, water.

Stages of the experiment

1. In a wide glass vessel filled with water, put a vial of alcohol ink.
2. There should be a small hole in the stopper of the vial.

Figure 5

Explanation of experience

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

Experiment No. 6 Fifteen matches on one

Devices and materials: 15 matches.

Stages of the experiment

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

Explanation of experience

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

Figure 6

Experience No. 7 Pot stand

Devices and materials: plate, 3 forks, napkin ring, saucepan.

Stages of the experiment

1. Put three forks in the ring.
2. Put a plate on this design.
3. Place a pot of water on a stand.

Figure 7

Figure 8

Explanation of experience

This experience is explained by the rule of leverage and stable equilibrium.

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 electricity or gasoline. We need only ... a candle for this.

1. Heat the needle and stick it with their heads into the candle. This will be the axis of our engine.
2. Place a candle with a knitting needle on the edges of two glasses and balance.
3. 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 disturbed, the other end of the candle will pull 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 fall, drop a drop, it will become easier, and our motor will start to work with might and main; gradually fluctuations of the candle will increase more and more.

Figure 10

Experience No. 9 Free exchange of fluids

Devices and materials: orange, glass, red wine or milk, water, 2 toothpicks.

Stages of the experiment

1. Carefully cut the orange in half, peel so that the skin is removed by a whole cup.
2. Poke two holes in the bottom of this cup side by side and put it in a glass. The diameter of the cup should be slightly larger than the diameter of the central part of the glass, then the cup will stay on the walls without falling to the bottom.
3. Lower the orange cup into the vessel one third of the height.
4. Pour red wine or colored alcohol into an orange peel. It will pass through the hole until the level of the wine reaches the bottom of the cup.
5. Then pour water almost to the brim. You can see how a stream of wine rises through one of the holes to the level of the water, while the heavier water passes through the other hole and begins to sink to the bottom of the glass. In a few moments the wine will be at the top and the water at the bottom.

Experience No. 10 Singing glass

Devices and materials: thin glass, water.

Stages of the experiment

1. Fill a glass with water and wipe the rim of the glass.
2. With a moistened finger, rub anywhere in the glass, she will sing.

Figure 11

Demonstration Experiments 1. Diffusion of liquids and gases

Diffusion (from Latin diflusio - spreading, spreading, scattering), the transfer of particles of different nature, due to the chaotic thermal motion of molecules (atoms). Distinguish between diffusion in liquids, gases and solids

Demonstration experiment "Observation of diffusion"

Devices and materials: cotton wool, ammonia, phenolphthalein, installation for observation of diffusion.

Stages of the experiment

1. Take two pieces of cotton wool.
2. We moisten one piece of cotton wool with phenolphthalein, the other with ammonia.
3. Let's bring the branches together.
4. Staining of cotton wool is observed in pink color due to the phenomenon of diffusion.

Figure 12

Figure 13

Figure 14

The phenomenon of diffusion can be observed using a special installation

1. Pour ammonia into one of the cones.
2. Moisten a piece of cotton wool with phenolphthalein and put it on top in a flask.
3. After a while, we observe the coloring of the fleece. This experiment demonstrates the phenomenon of diffusion at a distance.

Figure 15

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

Figure 16

To demonstrate this experiment, let's take two identical glasses. Pour cold water into one glass, hot water into the other. Add to glasses blue vitriol, we observe that in hot water copper sulfate dissolves faster, which proves the dependence of diffusion on temperature.