Elective course: "Practical and experimental physics." Presentation for a physics lesson (grade 10) on the topic: experimental work in physics “Change in pressure”

Job description: This article may be useful to physics teachers working in grades 7-9 using programs from various authors. It provides examples of home experiments and experiments carried out using children's toys, as well as qualitative and experimental problems, including solutions, distributed by grade level. The material in this article can also be used by students in grades 7-9 who have advanced cognitive interest and a desire to conduct independent research at home.

Introduction. When teaching physics, as is known, great value has a demonstration and laboratory experiment, bright and impressive, it affects the feelings of children, arouses interest in what is being studied. To create interest in physics lessons, especially in primary grades, you can, for example, demonstrate children's toys during lessons, which are often easier to use and more effective than demonstration and laboratory equipment. Using children's toys is very beneficial because... They make it possible to demonstrate very clearly, on objects familiar from childhood, not only certain physical phenomena, but also the manifestation of physical laws in the surrounding world and their application.

When studying some topics, toys will be almost the only visual aids. The method of using toys in physics lessons is subject to the requirements for various types school experiment:

1. The toy should be colorful, but without unnecessary details for the experience. All minor details that are not of fundamental importance in this experiment should not distract the attention of students and therefore they either need to be covered or made less noticeable.

2. The toy should be familiar to students, because increased interest in the design of the toy may obscure the essence of the demonstration itself.

3. Care should be taken to ensure the clarity and expressiveness of experiments. To do this, you need to choose toys that most simply and clearly demonstrate this phenomenon.

4. The experience must be convincing and not contain irrelevant this issue phenomena and not give rise to misinterpretation.

Toys can be used during any stage training session: when explaining new material, during frontal experimentation, solving problems and consolidating material, but the most appropriate, in my opinion, is the use of toys in home experiments and independent research work. The use of toys helps to increase the number of home experiments and research projects, which undoubtedly contributes to the development of experimental skills and creates conditions for creative work over the material being studied, in which the main effort is directed not at memorizing what is written in the textbook, but at setting up an experiment and thinking about its result. Experiments with toys will be both learning and play for students, and a game that certainly requires effort of thought.

The importance and types of independent experiment of students in physics. When teaching physics in high school experimental skills are formed by performing independent laboratory work.

Teaching physics cannot be presented only in the form of theoretical classes, even if students are shown demonstrations in class. physical experiments. To all types of sensory perception, it is imperative to add “work with your hands” in classes. This is achieved when students perform a laboratory physical experiment, when they themselves assemble installations and carry out measurements physical quantities, perform experiments. Laboratory classes arouse very great interest among students, which is quite natural, since in this case the student learns about the world around him on the basis of his own experience and his own feelings.

The importance of laboratory classes in physics lies in the fact that students develop ideas about the role and place of experiment in knowledge. When performing experiments, students develop experimental skills, which include both intellectual and practical skills. The first group includes the skills to: determine the purpose of the experiment, put forward hypotheses, select instruments, plan an experiment, calculate errors, analyze the results, draw up a report on the work done. The second group includes the skills to assemble an experimental setup, observe, measure, and experiment.

In addition, the significance of the laboratory experiment lies in the fact that when performing it, students develop such important personal qualities as accuracy in working with instruments; maintaining cleanliness and order in the workplace, in the notes made during the experiment, organization, persistence in obtaining results. They develop a certain culture of mental and physical labor.

In the practice of teaching physics at school, three types of laboratory classes have developed:

Frontal laboratory work in physics;

Physical workshop;

Home experimental work in physics.

Front laboratory work- this is the kind practical work when all students in a class simultaneously perform the same type of experiment using the same equipment. Front-end laboratory work is most often performed by a group of students consisting of two people; sometimes it is possible to organize individual work. Accordingly, the office should have 15-20 sets of instruments for front-end laboratory work. Total quantity There will be about a thousand such devices. The names of frontal laboratory work are given in the curriculum. There are quite a lot of them, they are provided for almost every topic of the physics course. Before carrying out the work, the teacher identifies the students’ readiness to consciously carry out the work, determines its purpose with them, discusses the progress of the work, the rules for working with instruments, and methods for calculating measurement errors. Front-end laboratory work is not very complex in content, is closely related chronologically to the material being studied and, as a rule, is designed for one lesson. Descriptions of laboratory work can be found in school physics textbooks.

Physics workshop carried out with the aim of repeating, deepening, expanding and generalizing the knowledge gained from different topics physics course; development and improvement of students' experimental skills through the use of more complex equipment, more complex experiments; formation of their independence in solving problems related to the experiment. Physics workshop is not related in time to the material being studied; it is usually held at the end academic year, sometimes at the end of the first and second half of the year and includes a series of experiments on a particular topic. Students perform physical practical work in a group of 2-4 people using various equipment; During the next classes there is a change of work, which is done according to a specially designed schedule. When drawing up a schedule, take into account the number of students in the class, the number of workshops, and the availability of equipment. Two teaching hours are allocated for each physics workshop, which requires the introduction of double physics lessons into the schedule. This presents difficulties. For this reason and due to the lack necessary equipment practice one-hour physical practicum work. It should be noted that two-hour work is preferable, since the work of the workshop is more complex than frontal laboratory work, they are performed on more complex equipment, and the share of independent participation of students is much greater than in the case of frontal laboratory work. Physical workshops are provided mainly by the programs of grades 9-11. In each class, approximately 10 hours of instructional time are allocated for the workshop. For each work, the teacher must draw up instructions, which should contain: title, purpose, list of instruments and equipment, brief theory, description of devices unknown to students, work plan. After completing the work, students must submit a report, which must contain: the title of the work, the purpose of the work, a list of instruments, a diagram or drawing of the installation, a plan for performing the work, a table of results, formulas by which the values ​​of quantities were calculated, calculations of measurement errors, conclusions. When assessing the work of students in a workshop, one should take into account their preparation for work, a report on the work, the level of development of skills, understanding of theoretical material, and the experimental research methods used.

Home experimental work. Home laboratory work is the simplest independent experiment that is performed by students at home, outside of school, without direct supervision by the teacher over the progress of the work.

The main objectives of experimental work of this type are:

Formation of the ability to observe physical phenomena in nature and in everyday life;

Formation of the ability to carry out measurements using measuring instruments used in everyday life;

Formation of interest in experiments and in the study of physics;

Formation of independence and activity.

Home laboratory work can be classified depending on the equipment used to perform it:

Works in which household items and improvised materials are used (measuring cup, tape measure, household scales, etc.);

Works in which they are used homemade devices(lever scales, electroscope, etc.);

Work performed on devices produced by industry.

Classification taken from.

In his book S.F. Pokrovsky showed that home experiments and observations in physics conducted by the students themselves: 1) enable our school to expand the area of ​​connection between theory and practice; 2) develop students’ interest in physics and technology; 3) awaken creative thought and develop the ability to invent; 4) teach students to be independent research work; 5) develop valuable qualities in them: observation, attention, perseverance and accuracy; 6) supplement classroom laboratory work with material that cannot be completed in class (a series of long-term observations, observation natural phenomena etc.), and 7) accustom students to conscious, purposeful work.

Home experiments and observations in physics have their own characteristic features, being an extremely useful addition to classroom and school practical work in general.

It has long been recommended that students have a home laboratory. it included, first of all, rulers, a beaker, a funnel, scales, weights, a dynamometer, a tribometer, a magnet, a watch with a second hand, iron filings, tubes, wires, a battery, and a light bulb. However, despite the fact that the set includes very simple devices, this proposal has not gained popularity.

To organize home experimental work for students, you can use the so-called mini-laboratory proposed by teacher-methodologist E.S. Obedkov, which includes many household items (penicillin bottles, rubber bands, pipettes, rulers, etc.) that is available to almost every schoolchild. E.S. Obyedkov developed a very large number interesting and useful experiences with this equipment.

It also became possible to use a computer to conduct a model experiment at home. It is clear that the corresponding tasks can only be offered to those students who have a computer and software and pedagogical tools at home.

In order for students to want to learn, the learning process must be interesting for them. What is interesting to students? To get an answer to this question, let us turn to excerpts from the article by I.V. Litovko, MOS(P)Sh No. 1, Svobodny “Homemade experimental tasks as an element of student creativity”, published on the Internet. This is what I.V. writes. Litovko:

“One of the most important tasks of the school is to teach students to learn, to strengthen their ability for self-development in the educational process, for which it is necessary to form in schoolchildren the corresponding stable desires, interests, and skills. An important role in this is played by experimental tasks in physics, which in their content represent short-term observations, measurements and experiments that are closely related to the topic of the lesson. The more observations of physical phenomena and experiments a student makes, the better he will understand the material being studied.

To study students’ motivation, they were asked the following questions and the results were obtained:

What do you like about studying physics? ?

a) problem solving -19%;

b) demonstration of experiments -21%;

  Oscillations and waves.
  Optics.

Tasks for independent work.
 Problem 1. Hydrostatic weighing.
Equipment: wooden ruler length 40 cm, plasticine, a piece of chalk, a measuring cup with water, thread, a razor blade, a tripod with a holder.
 Exercise.
Measure

• density of plasticine;
• chalk density;
• a mass of wooden ruler.

Notes:

1. It is advisable not to wet the piece of chalk - it may fall apart.
2. The density of water is considered equal to 1000 kg/m3

Problem 2. Specific heat of dissolution of hyposulfite.
When hyposulfite is dissolved in water, the temperature of the solution drops significantly.
Measure the specific heat of solution of a given substance.
The specific heat of solution is the amount of heat required to dissolve a unit mass of a substance.
The specific heat capacity of water is 4200 J/(kg × K), the density of water is 1000 kg/m 3.
Equipment: calorimeter; beaker or measuring cup; scales with weights; thermometer; crystalline hyposulfite; warm water.

Problem 3. Mathematical pendulum and free fall acceleration.

Equipment: tripod with foot, stopwatch, piece of plasticine, ruler, thread.
Exercise: Measure the acceleration of gravity using a mathematical pendulum.

Problem 4. Refractive index of the lens material.
Exercise: Measure the refractive index of the glass the lens is made from.

Equipment: biconvex lens on a stand, light source (light bulb on a stand with a current source and connecting wires), screen on a stand, caliper, ruler.

Problem 5. “Rod vibrations”

Equipment: tripod with foot, stopwatch, knitting needle, eraser, needle, ruler, plastic cap from a plastic bottle.

• Investigate the dependence of the oscillation period of the resulting physical pendulum on the length of the upper part of the spoke. Plot a graph of the resulting relationship. Check the feasibility of formula (1) in your case.
• Determine, as accurately as possible, the minimum period of oscillation of the resulting pendulum.
• Determine the value of the acceleration due to gravity.

Task 6. Determine the resistance of the resistor as accurately as possible.
Equipment: current source, resistor with known resistance, resistor with unknown resistance, glass (glass, 100 ml), thermometer, watch (you can use your wristwatch), graph paper, piece of foam plastic.

Problem 7. Determine the coefficient of friction of the block on the table.
Equipment: block, ruler, tripod, thread, weight of known mass.

Problem 8. Determine the weight of a flat figure.
Equipment: flat figure, ruler, weight.

Task 9. Investigate the dependence of the speed of the stream flowing out of the vessel on the height of the water level in this vessel.
Equipment: tripod with coupling and foot, glass burette with scale and rubber tube; spring clip; screw clamp; stopwatch; funnel; cuvette; glass of water; sheet of graph paper.

Problem 10. Determine the temperature of water at which its density is maximum.
Equipment: glass of water, at temperature t = 0 °C; metal stand; thermometer; spoon; watch; small glass.

Problem 11. Determine the breaking force T threads, mg< T .
Equipment: a strip whose length 50 cm; thread or thin wire; ruler; load of known mass; tripod.

Problem 12. Determine the coefficient of friction of a metal cylinder, the mass of which is known, on the table surface.
Equipment: two metal cylinders of approximately the same mass (the mass of one of them is known ( m = 0.4 - 0.6 kg)); length ruler 40 - 50 cm; Bakushinsky dynamometer.

Task 13. Explore the contents of a mechanical “black box”. Determine the characteristics of a solid body enclosed in a “box”.
Equipment: dynamometer, ruler, graph paper, “black box” - a closed jar partially filled with water containing solid with a rigid wire attached to it. The wire comes out of the jar through a small hole in the lid.

Problem 14. Determine the density and specific heat capacity of an unknown metal.
Equipment: calorimeter, plastic beaker, bath for developing photographs, measuring cylinder (beaker), thermometer, threads, 2 cylinders of unknown metal, vessel with hot ( t g = 60° –70°) and cold ( t x = 10° – 15°) water. Specific heat capacity of water c in = 4200 J/(kg × K).

Problem 15. Determine the Young's modulus of steel wire.
Equipment: tripod with two legs for attaching equipment; two steel rods; steel wire (diameter 0.26 mm); ruler; dynamometer; plasticine; pin.
Note. The wire stiffness coefficient depends on the Young's modulus and the geometric dimensions of the wire as follows k = ES/l, Where l– wire length, a S– its cross-sectional area.

Task 16. Determine the concentration of table salt in the aqueous solution given to you.
Equipment: glass jar volume 0.5 l; a vessel with an aqueous solution of table salt of unknown concentration; AC power supply with adjustable voltage; ammeter; voltmeter; two electrodes; connecting wires; key; set of 8 weighed amounts of table salt; graph paper; container with fresh water.

Problem 17. Determine the resistance of a millivoltmeter and milliammeter for two measurement ranges.
Equipment: millivoltmeter ( 50/250 mV), milliammeter ( 5/50 mA), two connecting wires, copper and zinc plates, pickled cucumber.

Problem 18. Determine the density of the body.
Equipment: irregularly shaped body, metal rod, ruler, tripod, vessel with water, thread.

Task 19. Determine the resistances of resistors R 1, ..., R 7, ammeter and voltmeter.
Equipment: battery, voltmeter, ammeter, connecting wires, switch, resistors: R 1 – R 7.

Problem 20. Determine the spring stiffness coefficient.
Equipment: spring, ruler, sheet of graph paper, block, mass 100 g.
Attention! Do not suspend a load from a spring, as this will exceed the elastic deformation limit of the spring.

Problem 21. Determine the coefficient of sliding friction of a match head on the rough surface of a matchbox.
Equipment: box of matches, dynamometer, weight, sheet of paper, ruler, thread.

Problem 22. The fiber optic connector part is a glass cylinder (refractive index n= 1.51), in which there are two round cylindrical channels. The ends of the part are sealed. Determine the distance between channels.
Equipment: connector part, graph paper, magnifying glass.

Problem 23. “Black Vessel”. A body is lowered into a “black vessel” of water on a string. Find the density of the body ρ m, its height l the water level in the vessel with the immersed body ( h) and when the body is outside the liquid ( h o).
Equipment. “Black vessel”, dynamometer, graph paper, ruler.
Density of water 1000 kg/m 3. Vessel depth H = 32 cm.

Problem 24. Friction. Determine the sliding friction coefficients of wooden and plastic rulers on the table surface.
Equipment. Tripod with foot, plumb line, wooden ruler, plastic ruler, table.

Problem 25. Wind-up toy. Determine the energy stored in the spring of a wind-up toy (car) at a fixed “winding” (number of turns of the key).
Equipment: a wind-up toy of known mass, a ruler, a tripod with a foot and a coupling, an inclined plane.
Note. Wind up the toy so that its mileage does not exceed the length of the table.

Problem 26. Determining the density of bodies. Determine the density of the weight (rubber plug) and the lever (wooden strip) using the proposed equipment.
Equipment: load of known mass (marked plug); lever (wooden slats); cylindrical glass ( 200 - 250 ml); thread ( 1 m); wooden ruler, vessel with water.

Problem 27. Studying the motion of the ball.
Raise the ball to a certain height above the table surface. Let's release him and watch his movement. If the collisions were absolutely elastic (sometimes they say elastic), then the ball would jump to the same height all the time. In reality, the height of the jumps is constantly decreasing. The time interval between successive jumps also decreases, which is clearly noticeable by ear. After some time, the bouncing stops and the ball remains on the table.
1 task – theoretical.
1.1. Determine the fraction of energy lost (energy loss coefficient) after the first, second, third rebound.
1.2. Obtain the dependence of time on the number of bounces.

Task 2 – experimental.
2.1. Using the direct method, using a ruler, determine the energy loss coefficient after the first, second, third impact.
It is possible to determine the energy loss coefficient using a method based on measuring the total time of motion of the ball from the moment it is thrown from a height H until the moment it stops bouncing. To do this, you have to establish the relationship between the total movement time and the energy loss coefficient.
2.2. Determine the energy loss coefficient using a method based on measuring the total time of motion of the ball.
3. Errors.
3.1. Compare the measurement errors of the energy loss coefficient in paragraphs 2.1 and 2.2.

Problem 28. Stable test tube.

• Find the mass of the test tube given to you and its outer and inner diameters.
• Calculate theoretically at what minimum height h min and maximum height h max of water poured into a test tube it will float stably in a vertical position, and find the numerical values ​​using the results of the first point.
• Determine h min and h max experimentally and compare with the results of step 2.

Equipment. A test tube of unknown mass with a scale pasted on, a vessel with water, a glass, a sheet of graph paper, a thread.
Note. It is prohibited to peel off the scale from the test tube!

Problem 29. Angle between mirrors. Define dihedral angle between mirrors with the greatest accuracy.
Equipment. A system of two mirrors, a measuring tape, 3 pins, a sheet of cardboard.

Problem 30. Ball segment.
A spherical segment is a body bounded by a spherical surface and a plane. Using this equipment, construct a graph of volume dependence V spherical segment of unit radius r = 1 from its height h.
Note. The formula for the volume of a spherical segment is not assumed to be known. Take the density of water equal to 1.0 g/cm3.
Equipment. A glass of water, a tennis ball of known mass m with a puncture, a syringe with a needle, a sheet of graph paper, tape, scissors.

Problem 31. Snow with water.
Define mass fraction snow in a mixture of snow and water at the time of issue.
Equipment. A mixture of snow and ice, a thermometer, a watch.
Note. Specific heat water c = 4200 J/(kg × °C), specific heat ice melting λ = 335 kJ/kg.

Problem 32. Adjustable “black box”.
In a “black box” with 3 outputs, an electrical circuit is assembled, consisting of several resistors with a constant resistance and one variable resistor. The resistance of the variable resistor can be changed from zero to a certain maximum value R o using an adjustment knob brought out.
Using an ohmmeter, examine the black box circuit and, assuming that the number of resistors in it is minimal,

• draw a diagram electrical circuit, enclosed in a “black box”;
• calculate the resistance of constant resistors and the value of R o;
• evaluate the accuracy of your calculated resistance values.

Problem 33. Measuring electrical resistance.
Determine the resistance of the voltmeter, battery and resistor. It is known that a real battery can be represented as an ideal one, connected in series with a certain resistor, and a real voltmeter can be represented as an ideal one, with a resistor connected in parallel.
Equipment. Battery, voltmeter, resistor with unknown resistance, resistor with known resistance.

Problem 34. Weighing ultra-light loads.
Using the proposed equipment, determine the mass m of a piece of foil.
Equipment. A jar of water, a piece of foam plastic, a set of nails, wooden toothpicks, a ruler with millimeter divisions or graph paper, a sharpened pencil, foil, napkins.

Problem 35. CVC CHA.
Determine the current-voltage characteristic (CVC) of the “black box” ( CHY). Describe the technique for measuring the current-voltage characteristic and plot its graph. Assess the errors.
Equipment. FC limiting the resistor with a known resistance R, multimeter in voltmeter mode, adjustable current source, connecting wires, graph paper.
Attention. Connect CHY to the current source bypassing the limiting resistor is strictly prohibited.

Problem 36. Soft spring.

• Experimentally investigate the dependence of the elongation of a soft spring under the action of its own weight on the number of coils of the spring. Give a theoretical explanation of the found relationship.
• Determine the elasticity coefficient and mass of the spring.
• Investigate the dependence of the period of oscillation of a spring on its number of turns.

Equipment: soft spring, tripod with foot, tape measure, clock with second hand, plasticine ball m = 10 g, graph paper.

Problem 37. Wire density.
Determine the density of the wire. Breaking the wire is not allowed.
Equipment: piece of wire, graph paper, thread, water, vessel.
Note. Density of water 1000 kg/m 3.

Problem 38. Friction coefficient.
Determine the coefficient of sliding friction of the bobbin material on wood. The bobbin axis must be horizontal.
Equipment: bobbin, thread length 0.5 m, wooden ruler fixed at an angle in a tripod, graph paper.
Note. During work, it is prohibited to change the position of the ruler.

Problem 39. The share of mechanical energy.
Determine the fraction of mechanical energy lost by the ball when falling without initial speed from above 1 m.
Equipment: tennis ball, ruler length 1.5 m, sheet of white paper A4, sheet of copy paper, glass plate, ruler; brick.
Note: for small deformations of the ball, Hooke’s law can (but not necessarily) be considered valid.

Problem 40. Vessel with water “black box”.
The “black box” is a vessel with water into which a thread is lowered, on which two weights are attached at some distance from each other. Find the masses of the loads and their densities. Assess the size of the loads, the distance between them and the water level in the vessel.
Equipment: “black box”, dynamometer, graph paper.

Problem 41. Optical “black box”.
An optical “black box” consists of two lenses, one of which is converging and the other is diverging. Determine their focal lengths.
Equipment: tube with two lenses (optical “black” box), light bulb, current source, ruler, screen with a sheet of graph paper, sheet of graph paper.
Note. The use of light from a distant source is allowed. Bringing the light bulb close to the lenses (that is, closer than the stands allow) is not allowed.

Home experimental tasks

Task 1.

Take a long, heavy book, tie it with a thin thread and

attach a 20 cm long rubber thread to the thread.

Place the book on the table and very slowly begin to pull on the end

rubber thread. Try to measure the length of the stretched rubber thread in

the moment the book begins to slide.

Measure the length of the stretched thread at uniform motion books.

Place two thin cylindrical pens (or two

cylindrical pencil) and also pull the end of the thread. Measure the length

stretched thread with uniform movement of the book on the rollers.

Compare the three results obtained and draw conclusions.

Note. The next task is a variation of the previous one. It

also aimed at comparing static friction, sliding friction and friction

Task 2.

Place a hexagonal pencil on the book parallel to its spine.

Slowly lift the top edge of the book until the pencil begins to

slide down. Slightly reduce the tilt of the book and secure it in this way.

position by placing something under it. Now the pencil if its again

put it on a book, it won't move. It is held in place by frictional force -

static friction force. But it’s worth weakening this force a little - and for this it’s enough

click on the book with your finger, and the pencil will crawl down until it falls on

table. (The same experiment can be done, for example, with a pencil case, a match

box, eraser, etc.)

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

around the axis?

To move a thick book on the table with one finger, you need to apply

some effort. And if you put two round pencils under the book or

handles, which in this case will be roller bearings, the book is easy

will move from a weak push with the little finger.

Carry out experiments and compare the static friction force and the friction force

sliding and rolling friction forces.

Task 3.

In this experiment, two phenomena can be observed at once: inertia, experiments with

Take two eggs: one raw and the other hard-boiled. Twist

both eggs on a large plate. You see that a boiled egg behaves differently,

than raw: it rotates much faster.

In a boiled egg, the white and yolk are tightly bound to their shell and

among themselves because are in a solid state. And when we spin

raw egg, then we first unwind only the shell, only then, due to

friction, layer by layer rotation is transferred to the white and yolk. Thus,

liquid white and yolk, by their friction between the layers, slow down the rotation

shells.

Note. Instead of raw and boiled eggs, you can twist two pans,

one of which contains water, and the other contains the same volume of cereal.

Center of gravity. Task 1.

Take two faceted pencils and hold them parallel in front of you,

placing a ruler on them. Start bringing the pencils closer together. There will be rapprochement

occur in alternating movements: first one pencil moves, then the other.

Even if you want to interfere with their movement, you will not succeed.

They will still move in turns.

As soon as the pressure on one pencil became greater and the friction became so

the second pencil can now move under the ruler. But after a while

time the pressure above it becomes greater than above the first pencil, and because

As friction increases, it stops. And now the first one can move

pencil. So, moving one by one, the pencils will meet in the very middle

ruler at its center of gravity. This can be easily seen from the divisions of the ruler.

This experiment can also be done with a stick, holding it on outstretched fingers.

By moving your fingers, you will notice that they, also moving alternately, will meet

under the very middle of the stick. True, this is only special case. Try it

do the same with a regular floor brush, shovel or rake. You

you will see that your fingers do not meet in the middle of the stick. Try to explain

why does this happen?

Task 2.

This is an old, very visual experience. Do you have a pocket knife (folding)

probably a pencil too. Sharpen your pencil so it has a sharp end

and stick a half-opened pocket knife a little above the end. Put

pencil point on index finger. Find such a position

half-open knife on a pencil, in which the pencil will stand on

finger, swaying slightly.

Now the question is: where is the center of gravity of a pencil and a pen

Task 3.

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

Place a matchbox on the table on its long narrow edge and

Place a match without a head on the box. This match will serve as a support for

another match. Take a match with its head and balance it on the support so that

so that it lies horizontally. Use a pen to mark the position of the center of gravity

matches with a head.

Scrape the head off the match and place the match on the support so that

The ink dot you marked was lying on the support. This is not for you now

succeed: the match will not lie horizontally, since the center of gravity of the match

moved. Determine the position of the new center of gravity and note that

Which side did he move? Mark with a pen the center of gravity of the match without

Bring a match with two points to class.

Task 4.

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

Cut out a figure of arbitrary (any fancy) shape from cardboard

and pierce several holes in different random places (it’s better if

they will be located closer to the edges of the figure, this will increase accuracy). Drive in

into a vertical wall or stand a small nail without a head or a needle and

hang a figure on it through any hole. Please note: figure

should swing freely on the nail.

Take a plumb line consisting of a thin thread and a weight and throw it

thread through the nail so that it points in the vertical direction

suspended figure. Mark the vertical direction on the figure with a pencil

Remove the figure, hang it from any other hole and again

Using a plumb line and a pencil, mark the vertical direction of the thread on it.

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

of this figure.

Pass a thread through the center of gravity you have found, at the end of which

make a knot and hang the figure on this thread. The figure must hold

almost horizontal. The more accurately the experiment is done, the more horizontal it will be

hold on to the figure.

Task 5.

Determine the center of gravity of the hoop.

Take a small hoop (such as a hoop) or make a ring out of

flexible twig, made of a narrow strip of plywood or rigid cardboard. Hang

it onto the nail and lower the plumb line from the hanging point. When the thread plumb

calms down, mark on the hoop the points of her touching the hoop and between

use these points to tighten and secure a piece of thin wire or fishing line

(you need to pull it hard enough, but not so much that the hoop changes its

Hang the hoop on a nail at any other point and do the same

most. The point of intersection of the wires or lines will be the center of gravity of the hoop.

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

Tie a thread to the intersection of wires or lines and hang it on

she has a hoop. The hoop will be in indifferent equilibrium since the center

the gravity of the hoop and the point of its support (suspension) coincide.

Task 6.

You know that the stability of the body depends on the position of the center of gravity and

on the size of the support area: the lower the center of gravity and larger area supports,

the more stable the body is.

Keeping this in mind, take a block or an empty matchbox and, placing it

alternately on squared paper at the widest, medium and widest

circle the smaller edge each time with a pencil to get three different

support area. Calculate the dimensions of each area in square centimeters

and write them down on paper.

Measure and record the height of the center of gravity position of the box for everyone

three cases (the center of gravity of the matchbox lies at the intersection

diagonals). Conclude at what position of the boxes is the most

sustainable.

Task 7.

Sit on a chair. Place your feet vertically without putting them under

seat. Sit completely straight. Try to stand up without bending forward,

without stretching your arms forward or moving your legs under the seat. You have nothing

If it works, you won't be able to get up. Your center of gravity, which is somewhere

in the middle of your body, will not allow you to stand up.

What condition must be met in order to stand up? You have to lean forward

or tuck your feet under the seat. When we get up, we always do both.

At the same time vertical line passing through your center of gravity should

be sure to go through at least one of the soles of your legs or between them.

Then the balance of your body will be quite stable, you can easily

you can get up.

Well, now try to stand up, holding dumbbells or an iron in your hands. Pull

hands forward. You may be able to stand up without bending over or bending your legs under

Inertia. Task 1.

Place a postcard on the glass and place a coin on the postcard

or a checker so that the coin is above the glass. Hit the postcard

click. The card should fly out and the coin (checker) should fall into the glass.

Task 2.

Place a double sheet of notebook paper on the table. One half

sheet, place a stack of books no lower than 25cm high.

Slightly lifting the second half of the sheet above the table level with both

With your hands, quickly pull the sheet towards you. The sheet should be freed from under

books, and the books must remain in place.

Place the book on the sheet of paper again and pull it now very slowly. Books

will move with the sheet.

Task 3.

Take a hammer, tie a thin thread to it, but let it

withstood the weight of the hammer. If one thread doesn't hold up, take two

threads Slowly lift the hammer up by the thread. The hammer will hang on

thread. And if you want to raise it again, but not slowly, but quickly

jerk, the thread will break (make sure that the hammer does not break when falling

nothing underneath). The inertia of the hammer is so great that the thread does not

survived. The hammer did not have time to quickly follow your hand, it remained in place, and the thread broke.

Task 4.

Take a small ball made of wood, plastic or glass. Make out

thick paper groove, place the ball in it. Move quickly across the table

groove and then suddenly stop it. The ball will continue by inertia

movement and will roll, jumping out of the groove.

Check where the ball will roll if:

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

b) pull the chute slowly and stop suddenly.

Task 5.

Cut the apple in half, but not all the way through, and leave it hanging

Now hit the blunt side of the knife with the apple hanging on top

something hard, such as a hammer. Apple continuing to move along

inertia, will be cut and split into two halves.

The same thing happens when chopping wood: if it fails

split a block of wood, they usually turn it over and hit it with the butt as hard as they can

ax on a solid support. Churbak, continuing to move by inertia,

is impaled deeper on the ax and splits in two.

In the first chapter thesis were considered theoretical aspects problems using electronic textbooks in the process of teaching physics at senior level secondary school. During theoretical analysis problems, we identified the principles and types of electronic textbooks, identified and theoretically substantiated the pedagogical conditions for the use of information technologies in the process of teaching physics at the senior level of secondary schools.

In the second chapter of the thesis, we formulate the purpose, objectives and principles of organizing experimental work. This chapter discusses the methodology for implementing the identified pedagogical conditions the use of electronic textbooks in the process of teaching physics at the senior level of secondary schools, the final paragraph provides an interpretation and assessment of the results obtained during the experimental work.

Purpose, objectives, principles and methods of organizing experimental work

In the introductory part of the work, a hypothesis was put forward that contained the main conditions that require testing in practice. In order to test and prove the proposals put forward in the hypothesis, we carried out experimental work.

Experiment at the Philosophical encyclopedic dictionary» is defined as a systematically conducted observation; systematic isolation, combination and variation of conditions in order to study the phenomena that depend on them. Under these conditions, a person creates the possibility of observations, on the basis of which his knowledge of the patterns in the observed phenomenon is formed. Observations, conditions and knowledge about patterns are the most significant, in our opinion, features that characterize this definition.

In the Psychology dictionary, the concept of experiment is considered as one of the main (along with observation) methods scientific knowledge in general, psychological research in particular. It differs from observation by active intervention in the situation on the part of the researcher, carrying out systematic manipulation of one or more variables (factors) and recording accompanying changes in the behavior of the studied object. A correctly set up experiment allows you to test hypotheses about cause-and-effect relationships and is not limited to establishing a connection (correlation) between variables. The most significant features, as experience shows, here are: the activity of the researcher, characteristic of the exploratory and formative types of experiment, as well as testing the hypothesis.

Highlighting essential features of the given definitions, as A.Ya. rightly writes. Nain and Z.M. Umetbaev, can be built and used next concept: An experiment is a research activity designed to test a hypothesis, unfolding in natural or artificially created controlled and controlled conditions. The result of this, as a rule, is new knowledge, including the identification of significant factors influencing efficiency pedagogical activity. Organization of an experiment is impossible without identifying criteria. And it is their presence that makes it possible to distinguish experimental activity from any other. These criteria, according to E.B. Kainova, there may be the presence of: the purpose of the experiment; hypotheses; scientific language of description; specially created experimental conditions; diagnostic methods; ways of influencing the subject of experimentation; new pedagogical knowledge.

Based on their goals, they distinguish between ascertaining, formative and evaluative experiments. The purpose of the ascertaining experiment is to measure the current level of development. In this case, we receive primary material for research and organization of a formative experiment. This is extremely important for the organization of any survey.

A formative (transforming, training) experiment aims not at a simple statement of the level of formation of this or that activity, the development of certain skills of the subjects, but their active formation. Here it is necessary to create a special experimental situation. The results of an experimental study often do not represent an identified pattern, a stable dependence, but a series of more or less fully recorded empirical facts. This data is often descriptive in nature, representing only more specific material that narrows the further scope of the search. The results of an experiment in pedagogy and psychology should often be considered as intermediate material and the initial basis for further research work.

Evaluation experiment (controlling) - with its help, after a certain period of time after the formative experiment, the level of knowledge and skills of the subjects is determined based on the materials of the formative experiment.

The purpose of the experimental work is to test the identified pedagogical conditions for the use of electronic textbooks in the process of teaching physics at the senior level of a secondary school and determine their effectiveness.

The main objectives of the experimental work were: selection of experimental sites for the pedagogical experiment; defining criteria for selecting experimental groups; development of tools and determination of methods for pedagogical diagnostics of selected groups; development of pedagogical criteria for identifying and correlating the levels of learning of students in control and experimental classes.

The experimental work was carried out in three stages, including: a diagnostic stage (carried out in the form of a confirmatory experiment); content stage (organized in the form of a formative experiment) and analytical (conducted in the form of a control experiment). Principles of carrying out experimental work.

The principle of comprehensiveness of scientific and methodological organization of experimental work. The principle requires security high level professionalism of the experimental teacher himself. The effectiveness of the implementation of information technologies in teaching schoolchildren is influenced by many factors, and, undoubtedly, its basic condition is the correspondence of the content of training to the capabilities of schoolchildren. But even in this case, problems arise in overcoming intellectual and physical barriers, and therefore, when using methods of emotional and intellectual stimulation of students’ cognitive activity, we provided methodological counseling that meets the following requirements:

a) problem-search material was presented using personalized explanatory methods and instructions to facilitate students’ assimilation of educational material;

b) various techniques and ways of mastering the content of the material being studied were proposed;

c) individual teachers had the opportunity to freely choose techniques and schemes for solving computerized problems, and work according to their original pedagogical techniques.

The principle of humanizing the content of experimental work. This is the idea of ​​the priority of human values ​​over technocratic, production, economic, administrative, etc. The principle of humanization was implemented by observing the following rules of pedagogical activity: a) the pedagogical process and educational relations in it are built on full recognition of the rights and freedoms of the student and respect for him;

b) know and during the pedagogical process rely on the positive qualities of the student;

c) constantly carry out humanistic education of teachers in accordance with the Declaration of the Rights of the Child;

d) ensure the attractiveness and aesthetics of the pedagogical space and the comfort of the educational relations of all its participants.

Thus, the principle of humanization, as I.A. Kolesnikova and E.V. Titova believe, provides schoolchildren with a certain social protection in an educational institution.

The principle of democratization of experimental work is the idea of ​​providing participants in the pedagogical process with certain freedoms for self-development, self-regulation, and self-determination. The principle of democratization in the process of using information technologies for teaching schoolchildren is implemented through compliance with the following rules:

a) create a pedagogical process open to public control and influence;

b) create legal support activities of students that help protect them from adverse environmental influences;

c) ensure mutual respect, tact and patience in the interaction between teachers and students.

The implementation of this principle helps to expand the capabilities of students and teachers in determining the content of education, choosing the technology for using information technology in the learning process.

The principle of cultural conformity of experimental work is the idea of ​​maximum use in upbringing, education and training of the environment in which and for the development of which it was created educational institution- culture of the region, people, nation, society, country. The principle is implemented based on compliance with the following rules:

a) understanding of cultural and historical value by the teaching community at school;

b) maximum use of family and regional material and spiritual culture;

c) ensuring the unity of national, international, interethnic and intersocial principles in the upbringing, education, and training of schoolchildren;

d) the formation of creative abilities and attitudes of teachers and students to consume and create new ones cultural values.

The principle of a holistic study of pedagogical phenomena in experimental work, which involves: the use of systemic and integrative - developmental approaches; a clear definition of the place of the phenomenon being studied in the holistic pedagogical process; disclosure driving forces and phenomena of the objects being studied.

We were guided by this principle when modeling the process of using educational information technologies.

The principle of objectivity, which involves: checking each fact using several methods; recording all manifestations of changes in the object under study; comparison of the data from your study with data from other similar studies.

The principle was actively used in the process of conducting the ascertaining and formative stages of the experiment, when using the electronic process in the educational process, as well as in analyzing the results obtained.

The principle of adaptation, which requires taking into account the personal characteristics and cognitive abilities of students in the process of using information technology, was used when conducting a formative experiment. The principle of activity, which assumes that correction of the personal semantic field and behavioral strategy can only be carried out during the active and intensive work of each participant.

The principle of experimentation aimed at active search participants in classes on new behavior strategies. This principle is important as an impetus for the development of creativity and initiative of the individual, as well as as a model of behavior in real life student

We can talk about learning technology using electronic textbooks only if: it satisfies the basic principles educational technology(pre-design, reproducibility, targeting, integrity); it solves problems that were not previously theoretically and/or practically solved in didactics; The means of preparing and transmitting information to the learner is the computer.

In this regard, we present the basic principles of the systemic implementation of computers in educational process, which were widely used in our experimental work.

The principle of new tasks. Its essence is not to transfer traditionally established methods and techniques to the computer, but to rebuild them in accordance with the new capabilities that computers provide. In practice, this means that when analyzing the learning process, losses are identified that occur from shortcomings in its organization (insufficient analysis of the content of education, poor knowledge of the real educational capabilities of schoolchildren, etc.). In accordance with the result of the analysis, a list of tasks is outlined that, due to various objective reasons (large volume, enormous time expenditure, etc.) are currently not being solved or are being solved incompletely, but which can be completely solved with the help of a computer. These tasks should be aimed at the completeness, timeliness and at least approximate optimality of the decisions made.

The principle of a systems approach. This means that the introduction of computers must be based on system analysis learning process. That is, the goals and criteria for the functioning of the learning process must be determined, structuring must be carried out, revealing the whole range of issues that need to be resolved in order for the designed system in the best possible way met the established goals and criteria.

Principles of the most reasonable typification of design solutions. This means that when developing software, the contractor must strive to ensure that the solutions he offers are suitable for the widest possible range of customers, not only in terms of the types of computers used, but also various types educational institutions.

In conclusion of this paragraph, we note that the use of the above methods with other methods and principles of organizing experimental work made it possible to determine the attitude towards the problem of using electronic textbooks in the learning process, and to outline specific ways effective solution problems.

Following the logic of theoretical research, we formed two groups - control and experimental. In the experimental group, the effectiveness of the selected pedagogical conditions was tested; in the control group, the organization of the learning process was traditional.

Educational features of the implementation of pedagogical conditions for the use of electronic textbooks in the process of teaching physics at senior levels are presented in paragraph 2.2.

The results of the work done are reflected in paragraph 2.3.