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 allow you 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 a frontal experiment, solving problems and consolidating material, but the most appropriate, in my opinion, is the use of toys in home experiments, independent research work Oh. 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.

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physics teacher
SAOU NPO Vocational School No. 3, Buzuluk

Pedsovet.su – thousands of materials for a teacher’s daily work

Experimental work to develop the ability of vocational school students to solve problems in physics.

Solving problems is one of the main ways to develop students' thinking, as well as consolidate their knowledge. Therefore, after analyzing the current situation, when some students could not solve even a basic problem, not only because of problems with physics, but also with mathematics. My task consisted of a mathematical side and a physical one.

In my work to overcome students’ mathematical difficulties, I used the experience of teachers N.I. Odintsova (Moscow, Moscow Pedagogical state university) and E.E. Yakovets (Moscow, high school No. 873) with correction cards. The cards are modeled after cards used in a mathematics course, but are focused on a physics course. Cards were made on all questions of the mathematics course that cause difficulties for students in physics lessons (“Converting units of measurement”, “Using the properties of a degree with an integer exponent”, “Expressing a quantity from a formula”, etc.)

Correction cards have similar structures:

rule→ pattern→ task

definition, actions → sample → task

actions → sample → task

Correction cards are used in following cases:

For preparation for tests and as material for independent study.

Students in a lesson or additional lesson in physics before a test, knowing their gaps in mathematics, can receive a specific card on a poorly understood mathematical question, study and eliminate the gap.

To work on mathematical mistakes made in the test.

After checking test work The teacher analyzes the students’ mathematical difficulties and draws their attention to the mistakes made, which they eliminate in class or in an additional lesson.

To work with students in preparation for the Unified State Exam and various Olympiads.

When studying the next physical law, and at the end of studying a small chapter or section, I suggest that students first time together, and then independently (homework) fill out table No. 2. At the same time, I give an explanation that such tables will help us in solving problems.

Table No. 2

Name

physical quantity

To this end, in the first problem-solving lesson, I show students with a concrete example how to use this table. And I propose an algorithm for solving elementary physical problems.

Determine which quantity is unknown in the problem.

Using table No. 1, find out the designation, units of measurement of the quantity, as well as the mathematical law connecting the unknown quantity and the quantities specified in the problem.

Check the completeness of the data necessary to solve the problem. If they are insufficient, use the appropriate values ​​from the lookup table.

Write a short notation, analytical solution and numerical answer to the problem in generally accepted notation.

I draw students’ attention to the fact that the algorithm is quite simple and universal. It can be applied to solving an elementary problem from almost any section school physics. Later, elementary tasks will be included as auxiliary tasks in more complex tasks. high level.

There are quite a lot of such algorithms for solving problems on specific topics, but it is almost impossible to remember them all, so it is more expedient to teach students not methods for solving individual problems, but a method for finding their solution.

The process of solving a problem consists of gradually correlating the conditions of the problem with its requirements. When starting to study physics, students do not have experience solving physics problems, but some elements of the process of solving problems in mathematics can be transferred to solving problems in physics. The process of teaching students the ability to solve physical problems is based on the conscious formation of their knowledge about the means of solution.

To this end, in the first problem-solving lesson, students should be introduced to a physical problem: present to them the condition of the problem as a specific plot situation in which some physical phenomenon occurs.

Of course, the process of developing students’ ability to independently solve problems begins with developing their ability to perform simple operations. First of all, students should be taught to correctly and completely write down a short note (“Given”). To do this, they are asked to identify the structural elements of a phenomenon from the text of several problems: a material object, its initial and final states, an influencing object and the conditions of their interaction. According to this scheme, first the teacher and then each of the students independently analyze the conditions of the tasks received.

Let us illustrate what has been said with examples of analyzing the conditions of the following physical problems (Table No. 3):

An ebony ball, negatively charged, is suspended on a silk thread. Will the force of its tension change if a second identical but positively charged ball is placed at the suspension point?

If a charged conductor is covered with dust, it quickly loses its charge. Why?

Between two plates located horizontally in a vacuum at a distance of 4.8 mm from each other, a negatively charged oil droplet weighing 10 ng is in equilibrium. How many “excess” electrons does the drop have if a voltage of 1 kV is applied to the plates?

Table No. 3

Structural elements of the phenomenon

The unmistakable identification of the structural elements of the phenomenon in the text of the problem by all students (after analyzing 5-6 problems) allows them to move on to the next part of the lesson, which aims at students mastering the sequence of operations. Thus, in total, students analyze about 14 problems (without completing the solution), which turns out to be sufficient for learning to perform the action “identifying the structural elements of a phenomenon.”

Table No. 4

Card - prescription

Assignment: express the structural elements of the phenomenon in

physical concepts and quantities

Indicative signs

Replace the material object indicated in the problem with the corresponding idealized object Express the characteristics of the initial object using physical quantities. Replace the influencing object specified in the problem with the corresponding idealized object. Express the characteristics of the influencing object using physical quantities. Express the characteristics of interaction conditions using physical quantities. Express the characteristics of the final state of a material object using physical quantities.

Next, students are taught to express the structural elements of the phenomenon under consideration and their characteristics in the language of physical science, which is extremely important, since all physical laws are formulated for certain models, and for the real phenomenon described in the problem, a corresponding model must be built. For example: “small charged ball” - a point charge; “thin thread” - the mass of the thread is negligible; “silk thread” - no charge leakage, etc.

The process of forming this action is similar to the previous one: first, the teacher, in a conversation with the students, shows with 2-3 examples how to perform it, then the students perform the operations independently.

The action “drawing up a plan for solving a problem” is formed in students immediately, since the components of the operation are already known to the students and have been mastered by them. After showing a sample of the action to each student, independent work a card is issued - the instruction “Drawing up a plan for solving the problem.” The formation of this action is carried out until it is performed accurately by all students.

Table No. 5

Card - prescription

“Drawing up a plan to solve a problem”

Operations Performed

Determine which characteristics of the material object have changed as a result of the interaction. Find out the reason behind this change in the state of the object. Write down the cause-and-effect relationship between the impact under given conditions and the change in the state of the object in the form of an equation. Express each member of the equation in terms of physical quantities that characterize the state of the object and the conditions of interaction. Select the required physical quantity. Express the required physical quantity in terms of other known ones.

The fourth and fifth stages of problem solving are carried out traditionally. After mastering all the actions that make up the content of the method for finding a solution to a physical problem, a complete list of them is written out on a card, which serves as a guide for students in independently solving problems over several lessons.

For me, this method is valuable because what students learn when studying one of the branches of physics (when it becomes a style of thinking) is successfully applied when solving problems in any section.

During the experiment, it became necessary to print algorithms for solving problems on separate sheets of paper for students to work on not only in class and after class, but also at home. As a result of work on developing subject-specific competence in problem solving, a folder was compiled didactic material for solving problems that any student could use. Then, together with the students, several copies of such folders were made for each table.

The use of an individual approach helped to develop the most important components in students educational activities- self-esteem and self-control. The correctness of the problem solving process was checked by the teacher and student consultants, and then more and more students began to help each other more and more often, involuntarily getting involved in the problem solving process.

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 a starting point 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 ensuring a high level of 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 of the 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 an electronic process in educational process, as well as when 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 computer is the means of preparing and transmitting information to the learner.

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.

  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 decreases greatly.
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 clamp; 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”. Define Characteristics solid, enclosed in a "box".
Equipment: dynamometer, ruler, graph paper, “black box” - a closed jar, partially filled with water, in which there is a solid body 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. Determine the 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. Spherical 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 of melting of ice 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 of an electrical circuit contained 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 method 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 format 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.

Experiment in physics. Physical workshop. Shutov V.I., Sukhov V.G., Podlesny D.V.

M.: Fizmatlit, 2005. - 184 p.

The experimental work included in the program of physics and mathematics lyceums as part of a physics workshop is described. The manual is an attempt to create a unified guide for conducting practical classes in classes and schools with in-depth study of physics, as well as for preparing for experimental rounds of high-level Olympiads.

Introductory material is traditionally devoted to methods of processing experimental data. The description of each experimental work begins with a theoretical introduction. The experimental part contains descriptions of experimental setups and tasks that regulate the sequence of students’ work when carrying out measurements. Samples of worksheet for recording measurement results, recommendations on methods for processing and presenting results, and requirements for reporting are provided. At the end of the descriptions there are suggested test questions, the answers to which students must prepare to defend their work.

For schools and classes with in-depth study of physics.

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INTRODUCTION

Physics workshop is an integral part of the physics course. A clear and deep understanding of the basic laws of physics and its methods is impossible without work in a physics laboratory, without independent practical training. In the physics laboratory, students not only test the known laws of physics, but also learn to work with physical instruments, master the skills of experimental research, and learn how to competently process measurement results and critically approach them.

This manual is an attempt to create a unified manual on experimental physics for conducting classes in physics laboratories of specialized physics and mathematics schools and lyceums. It is designed for students who do not have experience working independently in a physics laboratory. Therefore, the descriptions of the work are carried out in detail and thoroughly. Particular attention is paid to the theoretical justification of the experimental methods used, issues of processing measurement results and assessing their errors.

The description of each experimental work begins with a theoretical introduction. The experimental part of each work contains descriptions of experimental setups and tasks that regulate the sequence of students’ work when carrying out measurements, samples of worksheet for recording measurement results, and recommendations on methods for processing and presenting results. At the end of the descriptions, test questions are offered, the answers to which students must prepare to defend their work.

On average for academic year Each student must complete 10-12 experimental papers in accordance with the curriculum.

The student prepares in advance for each task. He must study the description of the work, know the theory to the extent specified in the description, the procedure for performing the work, have a previously prepared laboratory journal with a summary of the theory and tables, and also, if necessary, have graph paper for completing the estimated schedule.

Before starting work, the student receives permission to work.

An approximate list of questions to obtain admission:

1. Purpose of the work.

2. Basic physical laws studied in the work.

3. Installation diagram and principle of its operation.

4. Measured quantities and calculation formulas.

5. The order of work.

Students allowed to perform work are required to follow the order of execution strictly in accordance with the description.

Work in the laboratory ends with preliminary calculations and discussion with the teacher.

By the next lesson, the student independently finishes processing the obtained experimental data, constructing graphs and preparing a report.

During the defense of the work, the student must be able to answer all questions on the theory in the full scope of the program, justify the adopted measurement and data processing methodology, and independently derive calculation formulas. The work is completed at this point, and the final final grade for the work is assigned.

Semester and annual grades are awarded upon successful completion of all work in accordance with the curriculum.

Well " Experimental physics" is practically implemented on complex laboratory equipment developed by the Educational and Methodological Laboratory of the Moscow Institute of Physics and Technology, which includes laboratory complexes on mechanics of a material point, mechanics of a solid body, molecular physics, electrodynamics, geometric and physical optics. Such equipment is available in many specialized physics and mathematics schools and lyceums in Russia.

Introduction.

Errors of physical quantities. Processing of measurement results.

Practical work 1. Measuring the volume of bodies of regular shape.

Practical work 2. Study of the rectilinear motion of bodies in the field of gravity using an Atwood machine.

Practical work 3. Dry friction. Determination of sliding friction coefficient.

Theoretical introduction to work on oscillations.

Practical work 4. Study of oscillations of a spring pendulum.

Practical work 5. Study of oscillations of a mathematical pendulum. Determination of free fall acceleration.

Practical work 6. Study of oscillations of a physical pendulum.

Practical work 7. Determination of the moments of inertia of bodies of regular shape using the method of torsional vibrations.

Practical work 8. Study of the laws of rotation of a rigid body on a cruciform Oberbeck pendulum.

Practical work 9. Determination of the ratio of molar heat capacities of air.

Practical work 10. Standing waves. Measuring wave speed in an elastic string.

Practical work 11. Determination of the ratio ср/с ι? for air in a standing sound wave.

Practical work 12. Study of the operation of an electronic oscilloscope.

Practical work 13. Measuring the frequency of oscillations by studying Lissajous figures.

Practical work 14. Determination of resistivity of nichrome wire.

Practical work 15. Determination of conductor resistance using the Wheatstone compensation method.

Practical work 16. Transient processes in a capacitor. Determination of capacity.

Practical work 17. Determination of tension electric field in a cylindrical conductor carrying current.

Practical work 18. Study of the operation of a source in a DC circuit.

Practical work 19. Study of the laws of reflection and refraction of light.

Practical work 20. Determination of focal lengths of converging and diverging lenses.

Practical work 21. The phenomenon of electromagnetic induction. Study magnetic field solenoid.

Practical work 22. Study of damped oscillations.

Practical work 23. Study of the phenomenon of resonance in an alternating current circuit.

Practical work 24. Fraunhofer diffraction by a slit. Measuring the slit width using the “wave method”.

Practical work 25. Fraunhofer diffraction. Diffraction grating as an optical device.

Practical work 26. Determination of the refractive index of glass using the “wave” method.

Practical work 27. Determination of the radius of curvature of a lens in an experiment with Newton’s rings.

Practical work 28. Study of polarized light.