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 use information technology in the process of teaching physics at the senior level of a comprehensive school.
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 at all, 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, we can construct the following 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 allows us to distinguish experimental activities from any other. These criteria, according to E.B. Kainova, there may be the presence of: the purpose of the experiment; hypotheses; scientific language descriptions; 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 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. Results experimental research 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 original 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 definition of methods pedagogical diagnostics 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 that make it easier for schoolchildren to learn educational material;
b) were offered various techniques and ways to master the content of the material being studied;
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 priority 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 for students’ activities that will 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 holistic learning pedagogical phenomena V 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 electronic process V educational process, as well as when analyzing the results obtained.
Adaptation principle that needs to be taken into account personal characteristics And cognitive abilities, learning 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 resulting from shortcomings in its organization are revealed (insufficient analysis of the content of education, poor knowledge real educational opportunities for 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.
Principle systematic approach. This means that the introduction of computers should be based on a systematic analysis of the 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 typing design solutions. This means that when developing software, the developer must strive to ensure that the solutions he proposes are as suitable as possible. to a wide circle customers not only in terms of the types of computers used, but also the different types of 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 to effectively solve the problem.
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.
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 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 junior classes, you can, for example, demonstrate children's toys in lessons, which are often easier to handle 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 experience, should not distract the attention of students and therefore they either need to be closed or made less noticeable.
2. The toy should be familiar to students, because increased interest to 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, not contain phenomena irrelevant to the given issue 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 developed by performing independent laboratory work.
Teaching physics cannot be presented only in the form theoretical studies, even if students are shown demos 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 laboratory tests physical experiment, when they assemble the installations themselves, take 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 based on own experience and your 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: collect experimental setup, observe, measure, experiment.
In addition, the significance of the laboratory experiment lies in the fact that when performing it, students develop such important personal qualities how to be careful when 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 educational programs. 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 textbooks in physics.
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. For each physical workshop work, two teaching hours, which requires the introduction of double physics lessons into the schedule. This presents difficulties. For this reason and due to the lack of necessary equipment, one-hour physical workshops are practiced. It should be noted that two-hour work is preferable, since the work of the workshop is more complex than frontal laboratory work; 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 students’ work in a workshop, one should take into account their preparation for work, report on work, level of skills, understanding theoretical material, 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 homemade instruments are used (lever scales, electroscope, etc.);
Work performed on industrially produced devices.
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) accustom students to 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 extremely useful addition for 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 clock with a second hand, iron filings, tubes, wires, battery, 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. Obedkov developed a very large number of interesting and useful experiments 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 “Home experimental tasks as an element of student creativity”, published on the Internet. This is what I.V. writes. Litovko:
“One of most important tasks schools - to teach students to learn, to strengthen their ability for self-development in the process of education, 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%;
The effectiveness of using experimental tasks in lessons is largely determined by their technological effectiveness, unpretentious equipment, and the breadth of the phenomena under consideration. Based on the simplest equipment and even household items, experimental task brings physics closer to us, transforming it in the students’ minds from an abstract system of knowledge into science that studies “the world around us.”
Mechanics
Task 1. Friction coefficient
Exercise. Measure the sliding friction coefficient of a wooden block on the surface of a board (ruler).
Equipment: block, board, tripod with foot, ruler 30(40) long cm.
Possible way solutions. We place the block on the board, in accordance with Figure 4. Gradually raising one end of the board, we obtain an inclined plane and achieve uniform sliding of the block. Since the static friction force is much more power sliding friction, it is necessary to push the bead a little at the beginning of sliding. To fix the desired tilt, use a tripod. We measure the height A and base length inclined plane b.
Measurements and error analysis:
We repeat the experiment several times. In this case, this must be done mainly because it is difficult to achieve uniform sliding of the block along the plane. The results are recorded in Table 2.
Table 2
Measurement errors
|
a, cm |
Yes, cm |
(Yes) 2 ,cm 2 |
in, cm |
Db, cm |
(Db) 2 ,cm 2 |
|
<a>=12,2 |
U( a) 2 = 1,81 |
U( b) 2 = 0,32 |
In addition to random errors, the total error, of course, also includes the usual reference errors: Yes = Db = 0.5 cm.This amounts to:
Thus we get:
a = 12.2 ± 1.1 cm, d = 8.6%
b = 27.4 ± 0.7 cm, d = 2.6%
Based on the results of the first experiment:
The final result of the friction coefficient measurement is:
m = 0.46 ± 0.05 d = 10.9%
Task 2. Measuring the height of a house
Exercise. Imagine that you were asked to use an empty tin can and a stopwatch to measure the height of a house. Would you be able to cope with the task? Tell us how to act.
Clue. If a can is thrown from the roof of a house, the sound of the can hitting earth's surface will be clearly audible.
Solution. Standing on the roof of the house, you need to release the can from your hands while simultaneously pressing the stopwatch start button. When you hear the sound of the can hitting the ground, you should stop the stopwatch. Stopwatch readings t are made up of the time the jar falls t 1 and time t 2, during which the sound of its impact on the earth’s surface will reach the observer.
The first time is related to the height of the house h as follows:
whereas the connection between h and t 2 has the form
Where With- speed of sound, which in calculations we will set equal to 340 m/sec.
Defining t 1 and t 2 of these expressions and substituting their values into the formula connecting t 1 , t 2 and t, we obtain the irrational equation
From which you can find the height of the house.
In an approximate calculation (especially if the house is low), the second term on the left can be considered small and discarded. Then
Molecular physics
Task 3. Pencil
Exercise. Estimate the mechanical work that must be done in order to uniformly raise a pencil floating in a vessel to the level of its lower end touching the surface of the water. Consider the position of the pencil to be vertical. Density of water With 0 = 1000 kg/m 3 .
Equipment: round pencil, almost full bottle with water, ruler.
Possible solution. We lower the pencil into the bottle - it will float like a float, in accordance with Figure 5. Let L- the length of the entire pencil, V- its volume, h- the length of the part of the pencil immersed in water, V 1 - its volume, S- cross-sectional area and d- pencil diameter. We'll find average density pencil With from the body floating condition:
With 0 gSh= сgSL, where With= With 0 hL.
Suppose we are constant speed We pull the pencil out of the water using a dynamometer. When the pencil floats freely, the dynamometer shows zero. If the pencil is completely pulled out of the water, the dynamometer will show the force, equal to weight R pencil:
F = P = mg = сgV = с0hLgSL = с0hgрd24
It turns out that the readings of the dynamometer when pulling the pencil out of the water change from 0 to P according to the linear law, in accordance with Figure 6. In this case mechanical work A will be equal to the area of the selected triangle:
A= 12Ph= With 0 h 2gрd 2 8.
For example, when h= 13,4 cm And d = 7,5 mm work is about 0.004 J.
Task 4. Alloy
Exercise. Determine the percentage (by weight) of tin in tin-lead solder. Assume that the volumes of lead and tin in the alloy are conserved. Lead Density With c = 11350 kg/m 3 , tin With 0 = 7300 kg/m 3 .
Equipment: ruler, weight (nut), cylindrical piece of solder, caliper or micrometer. Possible solution. This problem is similar to Archimedes' problem of determining the proportion of gold in the royal crown. However, for experiments, tin-lead solder is easier to obtain than corona.
Measuring the diameter of a piece of solder D and its length L, find the volume of a cylindrical piece of solder:
V =рD 2 L 4
We will determine the mass of solder by making lever scales. To do this, balance the ruler on the edge of the table (on a pencil, on a ballpoint pen, etc.). Then using the nut known mass, we balance a piece of solder on a ruler and, using the equality of moments of force, we find the mass of the solder m. Let us write down the obvious equalities for the masses, volumes and densities of lead and tin:
m = m c +m o = ccV c +s o V o , V = V c +V o .
Solving these equations together, we find the volume of tin, its mass and its share in the total mass:
V o = rh o cV?mrh o c?rh oo , mo = с o V o , m o m = rh oo V o m
Problem 5. Surface tension
Exercise. Determine the coefficient of surface tension of water.
Equipment: plate, water, spoon, ruler, piece of flat aluminum wire length 15-20 cm and density 2700 kg/m 3 , micrometer, alcohol, cotton wool.
Possible solution. Pour an almost full plate of water. Place a wire on the edge of the plate so that one end touches the water and the other is outside the plate. The wire serves two functions: it is a lever scale and an analogue of the wire frame that is usually pulled out of the water to measure surface tension. Depending on the water level, there may be various provisions wire. The most convenient for calculations and measurements is the horizontal arrangement of the wire at a water level of 1-1.5 mm below the edge of the plate, in accordance with Figure 7. Using a spoon, you can adjust the level by adding or draining water. The wire should be pulled out of the plate until the film of water under the wire begins to break. In this emergency situation the film has a height of 1.5-2 mm, and we can say that the surface tension forces applied to the wire are directed almost vertically downward.
Let m- mass of wire, L = L 1 +L 2 - wire length, m/L- mass per unit length of wire. Let us write down the condition for the equilibrium of the wire relative to the edge of the plate, i.e. equality of moments of forces:
F p (L 1 ?x 2)+m 1 gL 12 = m 2 gL 22 .
Let's substitute the surface tension force here F p =2x at, masses
m 1 =L 1 mL, m 2 = L 2 mL, m= cV= srd 2 L 4
and express the surface tension coefficient at. Measurements and calculations will be simplified if water wets the entire length L 1 . Finally we get
at= srd 2 g 8((LL 1 ?1) 2 ?1).
Quantities L And L 1 are measured with a ruler, and the diameter of the wire d- micrometer.
For example, when L = 15 cm, L 1 = 5,4 cm, d = 1,77 mm we get O = 0,0703 N/m, which is close to the table value of 0.0728 N/m.
Problem 6. Air humidity
Exercise. Determine the relative humidity in the room.
Equipment: glass room thermometer, household refrigerator, pressure table saturated vapors water at different temperatures.
Possible solution. At the usual method When measuring humidity, the object is cooled below the dew point and it “fogs up.” Let's do the opposite. Refrigerator temperature (about +5 ° C) is much lower than the dew point for room air. Therefore, if you take a cooled glass thermometer out of the refrigerator, it will immediately “fog up” - the glass case will become opaque from moisture. Then the thermometer will begin to heat up, and at some point the condensed moisture on it will evaporate - the glass will become transparent. This is the dew point temperature, from which the relative humidity can be calculated using a table.
Problem 7. Evaporation
Exercise. Pour an almost full glass of water and place it in a warm place in the room so that the water evaporates faster. Measure with a ruler entry level water and record the start time of the experiment. After a few days, the water level will drop due to evaporation. Measure new level water and record the end time of the experiment. Determine the mass of water evaporated. On average, how many molecules escape from the surface of the water in 1 second? Approximately how many molecules are there on the surface of the water in the glass? Compare these two numbers. Take the diameter of a water molecule to be equal to d 0 = 0,3 nm. Knowing the specific heat of vaporization, determine the rate of heat transfer ( J/s) water from environment.
Possible solution. Let d- inner diameter of the glass, With- density of water, M- molar mass of water, r- specific heat of vaporization, D h- decrease in water level over time t. Then the mass of evaporated water is
m= cv= With D hS= With D hрd 2 4.
This mass contains N = mN A /M molecules, where N A- Avogadro's constant. The number of molecules evaporated in 1 second is
N 1 = Nt= mN A Mt.
If S= pd 2/4 is the surface area of water in a glass, and S 0 = pd 2 0 /4 is the cross-sectional area of one molecule, then on the surface of water in a glass there is approximately
N 2 = SS 0 = (dd 0) 2 .
Water receives heat per unit time for evaporation
Qt= rmt.
If you make any calculations related to molecules, you always get interesting results. For example, let in time t= 5 days in a glass with diameter d = 65 mm the water level dropped by D h = 1 cm. Then we get that 33 turned into steam G water, for 1 With evaporated N 1 = 2.56?10 18 molecules, on the surface of the water in the glass there were N 2 = 4.69?1016 molecules, and 0.19 came from the environment W heat. The interesting thing is the attitude N 1 /N 2? 54, from which it is clear that for 1 With As many molecules evaporated as could fit in a glass in 54 layers of water.
Problem 8. Dissolution
Exercise. By pouring salt or sugar into boiling water, you will notice that the boiling stops for a short time due to the decrease in water temperature. Determine the amount of heat required to dissolve 1 kg baking soda in water at room temperature.
Equipment: homemade calorimeter, thermometer, water, soda, graduated cylinder (glass), load of known mass (nut weighing 10 G), plastic spoon.
Possible solution. The task includes an additional design task for the manufacture of a simple homemade calorimeter. For the internal vessel of the calorimeter, take a regular aluminum can with a volume of 0.33 liters. The top lid of the jar is removed so that an aluminum glass is obtained (weighing only 12 G) with a rigid upper rim. A slot is made inside the top rim so that the water can completely drain out of the jar. The outer plastic shell is made from plastic bottle volume 1.5 l. The bottle is cut into three parts, upper part is removed, and the middle and lower parts are inserted into each other with some force and tightly fix the inner aluminum can in a vertical position. (If there is no calorimeter, then experiments can be carried out in a disposable plastic cup, the mass and heat transfer of which can be neglected).
First you need to make two measurements: 1) determine how much soda fits in a spoon (to do this, you need to look in a culinary reference book or “scoop out” a packet of soda of a known mass with this spoon); 2) decide on the amount of water - in a small amount of water the solution will immediately become saturated and part of the soda will not dissolve; in a large amount of water the temperature will change by fractions of a degree, which will complicate measurements.
Obviously, the amount of heat required to dissolve a substance is proportional to the mass of this substance: Q~m. To record equality, you should enter a proportionality coefficient, for example z, which can be called “specific heat of solution”. Then
Q= zm.
The dissolution of soda is carried out due to the energy released when the vessel with water cools. The value of z is found from the following heat balance equation:
mvcv(t 2 -t 1 )+ma cc (t 2 -t 1 ) = zm.
Where m v is the mass of water in the calorimeter, m a is the mass of the internal aluminum cup of the calorimeter, m- mass of dissolved soda, ( t 2 -t 1) - decrease in temperature in the calorimeter. The mass of the internal vessel of the calorimeter can be easily found using the rule of moments of forces, balancing the vessel and a load of known mass using a ruler and thread.
Measurements and calculations show that when m= 6 g and m v = 100 G the water cools down by 2-2.5 degrees C, and the value z turns out to be equal to 144-180 kJ/kg.
Task 9. Pot capacity
Exercise. How can you find the capacity of a pan using scales and a set of weights?
Clue. Weigh the empty pan, and then the pan with water.
Solution. Let the mass of the empty pan be m 1, and after filling with water it is m 2. Then the difference m 2 -m 1 gives the mass of water in the volume of the pan. Dividing this difference by the density of water With, find the volume of the pan:
Problem 10. How to separate the contents of a glass
Exercise. There is a cylindrical glass filled to the brim with liquid. How to divide the contents of a glass into two completely equal parts, having another vessel, but of a different shape and slightly smaller size?
Clue. Think about how you can draw a plane dividing the cylinder into two parts of equal volume.
Solution. If through points M And N mentally draw the plane as shown in Figure 1 A, then it will cut the cylinder into two symmetrical and therefore equal in volume figures, in accordance with Figure 8. From here follows the solution to the problem.
Gradually tilting the glass, you need to pour out the liquid it contains until the bottom just appears (Figure 1 b). At this moment, exactly half of the liquid will remain in the glass.
Electricity
Problem 11. Electric black box
A black box is an opaque, closed box that cannot be opened to examine its internal structure. Inside the box are several electrical elements, connected to each other in a simple electrical circuit. Typically these elements are: current sources, fixed and variable resistors, capacitors, inductors, semiconductor diodes. There are several terminals on the outside of the box.
The main goal of the "black box" task: making the minimum number electrical measurements using external pins, “decipher” the “black box”, i.e.:
- - establish which electrical devices are inside the “black box”.
- - establish a diagram of their connection.
- - determine the values (resistance values of resistors, capacitor capacitances, etc.)
Exercise. Three resistors are connected to each other and placed in a “black box” with three terminals, in accordance with Figure 9. Exactly the same resistors are connected to each other in a different way and placed in a second “black box” with three terminals. Determine the resistance of each resistor. Jumpers are prohibited.
Equipment: multimeter.
Measuring the resistance between the terminals gave the following results:
Box No. 1: R 1-2 = 12Ohm, R 2-3 = 25Ohm, R 1-3 = 37Ohm
Box No. 2: R 1-2 = 5,45Ohm, R 2-3 = 15Ohm, R 1-3 = 20,45Ohm
Possible solution. There are four possible ways of connecting three resistors to three outer terminals so that the three measurements give different meaning resistances:
1) sequential, 2) mixed, 3) star, 4) triangle, in accordance with Figure 10.
We will show the sequence of searching for answers.
A characteristic feature of the first two schemes is that one of the measurements is equal to the sum of the other two, which corresponds to the conditions of the problem:
Consequently, in one box there is a serial connection, but then in the other there is a mixed connection, since the measurement results do not match, although the resistor values are the same.
It is known that the relation is always satisfied
And since R 1-3 on the left more than R 1-3 on the right, then in the left box (No. 1) there is a serial connection, and in the right (No. 2) there is a mixed connection.
The series connection in the left box contains resistors with values of 12 or 25 Ohm. Since neither one nor the other value is observed as part of a mixed connection, therefore, the value of one of the resistors R 1 = 15Ohm.
Other denominations: R 2 = 12Ohm And R 3 = 10Ohm.
Obviously, the same results can be reached using a different chain of reasoning.
Note also that 5 more combinations of schemes with two “black boxes” from the above four are possible. The most cumbersome mathematical part of the problem is to “decipher” the black box, which is known to contain a triangle.
In conclusion, we note that not everything can go as smoothly as in this example. Resistance values or other electrical quantities, naturally, contain errors. And, for example, the ratio can only be satisfied approximately.
Problem 12. Room temperature
Exercise. There is snow outside the window, but the room is warm. Unfortunately, there is nothing to measure the temperature with - there is no thermometer. But there is a battery, a very accurate voltmeter and the same ammeter, as much copper wire as you like and a detailed physical reference book. Is it possible to use them to find the air temperature in the room?
Clue. When a metal is heated, its resistance increases linearly.
Solution. Let's connect a battery in series, a coil of wire and turn on the ammeter so that it shows the voltage on the coil, in accordance with Figure 11. We record the instrument readings and calculate the resistance of the coil at room temperature:
After this, we will bring snow from the street, immerse a coil of it in it and, after waiting a little so that the snow begins to melt and the wire begins to warm up, we will determine the resistance of the wire in the same way R 0 at the temperature of melting snow, i.e. at 0 є WITH. Using then the relationship between the resistance of the conductor and its temperature
find the air temperature in the room:
The calculation uses the value temperature coefficient resistance b, taken from the reference book. In the room temperature range for pure copper b= 0,0043 hail - 1. If the content of impurities in the copper from which the wire is made is not particularly high, and electrical measuring instruments have an accuracy class of 0.1, then the air temperature can be determined with an error of significantly less than one degree.
Optics
Problem 13.
Exercise. We need to find the radius spherical mirror(or radius of curvature concave lenses) using a stopwatch and a steel ball of known radius. How to do this?
Clue. The center of a ball rolling on the surface of a mirror makes the same motion as a pendulum.
Solution. Place the mirror horizontally and lower the ball onto it. If the ball is not lowered to the lowest point, it will begin to move along the surface of the mirror. It is not difficult to guess that if the ball moves without rotation (i.e. slides along the surface of the mirror), then its movement is completely similar to the movement of a pendulum with a suspension length R-r. Then from the pendulum formula
we can find the quantity we are interested in:
Period T determined using a stopwatch, and r known by condition.
Since the friction is usually high enough to cause the ball to move along the surface of the mirror with rotation, this solution does not agree well with experiment. In fact
Here is an example of a research task for the entire lesson.
Problem 14. Features of oscillation of a torsion pendulum.
Exercise. Explore the features of oscillation of a torsional pendulum and describe the main patterns of its movement.
Equipment: tripod with coupling and foot, pieces of copper, steel and nichrome wire about 1 m and various diameters, for example 0.3, 0.50, 0.65, 1.0 mm, thin light wooden stick 15-20 long cm, plasticine, paperclip, ruler, protractor, stopwatch.
The general appearance of the torsion pendulum should be in accordance with Figure 12. A paper clip, bent in a certain way, serves to balance the rod with weights. The pendulum, removed from the state of equilibrium, begins to perform a rotational-oscillatory motion.
You need to make a pair of balls from plasticine in advance. different weights. The masses of the balls are proportional to the cube of their diameters, so it is possible to build a series, for example: m 1 = 1, m 2 = 2,5, m 3 = 5,2, m 3 = 6,8, m 4 = 8,3 rel. units
The diameter of the wires can be given to students in advance or they can be given the opportunity to make these measurements themselves using a caliper or micrometer.
Note. The success of the study largely depends on correct selection equipment, especially the diameters of the issued wires. In addition, it is desirable that the suspension of the torsion pendulum be in a tense state during the experiments, for which the masses of the loads must be large enough.
The subject of the study of a torsional pendulum follows from the assumption of the harmonic nature of its oscillations. General list experimental observations that can be implemented on this problem and on the proposed equipment is quite large. We present the simplest and most accessible ones.
- - Does the period of oscillation depend on the amplitude (angle of rotation)?
- - Does the period of oscillation depend on the length of the pendulum's suspension?
- - Does the period of oscillation of a pendulum depend on the mass of the loads?
- - Does the period of oscillation of a pendulum depend on the position of the weights on the rod?
- - Does the period of oscillation depend on the diameter of the wire?
Naturally, it is required not only to answer the questions posed in monosyllables, but also to examine the nature of the expected dependencies.
Using the method of analogies, we put forward hypotheses about the oscillations of a torsion pendulum, comparing it with a mathematical pendulum studied by school curriculum. We take as a basis the period of oscillation and its dependence on various parameters of the pendulum. We outline the following hypotheses. Period of oscillation of a torsion pendulum:
At small angles of rotation it does not depend on the amplitude;
- - proportional to the square root of the length of the suspension - T;
- - proportional to the square root of the mass of the load - T;
- - proportional to distance from the suspension center to the load centers - Tr;
- - inversely proportional to the square of the wire diameter - T1/d 2 .
In addition, the oscillation period depends on the suspension material: copper, steel, nichrome. There are also a number of hypotheses here, we suggest testing them yourself.
1. We study the dependence of the period of oscillation of the pendulum on the amplitude (angle of rotation). The measurement results are presented in Table 3:
Table 3
Dependence of the period of oscillation of a pendulum on amplitude
L= 60cm, m = 8,3g, r = 12cm, d = 0,5mm
Conclusion. Within limits of up to 180, the dependence of the period of oscillation of the torsion pendulum on the amplitude is not detected. The scatter of measurement results can be explained by errors in measuring the oscillation period and random reasons.
To “open” other dependencies, you need to change only one parameter, leaving all others unchanged. Mathematical processing of results is best done graphically.
2. We study the dependence of the period of oscillation of the pendulum on its length: T = f(l). At the same time, we do not change m, r, d. The measurement results are presented in Table 4:
Table 4
Dependence of the period of oscillation of a pendulum on length
m = 8,3rel. units, r = 12cm, d = 0,5mm
Dependency graph T from l represents a curve of an increasing line, similar to a dependence, in accordance with Figure 13 A T 2 = l, in accordance with Figure 13, b.
Conclusion. The period of oscillation of a torsion pendulum is directly proportional to the square root of the length of the suspension. Some scatter of points can be explained by measurement errors in the period of oscillation and the length of the pendulum
3. We study the dependence of the period of oscillation of the pendulum on the mass of the loads: T=f(m). At the same time, we do not change l, r, d. The measurement results are presented in Table 5:
Table 5
Dependence of the period of oscillation of a pendulum on the mass of loads
l = 0,6m, r = 12cm, d = 0,5mm
Dependency graph T from m represents a curve of an increasing line, similar to a dependence, in accordance with Figure 14 A. To make sure of this, we build a dependency T 2 =f(m), according to Figure 14 b.
Conclusion. The period of oscillation of a torsion pendulum is directly proportional to the square root of the mass of the loads. Some scatter of points can be explained by measurement errors of the oscillation period and masses of the loads, as well as random reasons.
4. We study the dependence of the period of oscillation of the pendulum on the position of the weights: T = f(r). At the same time, we do not change l, m, d. The measurement results are presented in Table 6:
Table 6
Dependence of the period of oscillation of the pendulum on the position of the weights
m = 8,3rel. units, l = 0,6m, d = 0,5mm
Conclusion. The period of oscillation of a torsion pendulum is directly proportional to the distance r. Some scatter of points can be explained by measurement errors of the oscillation period and distance r, as well as random reasons.
We study the dependence of the period of oscillation of the pendulum on the diameter of the wire: T = f(d), in accordance with Figure 15 . At the same time we do not change m, r, l.
The measurement results are presented in Table 7.
Table 7
Dependence of the period of oscillation of a pendulum on the diameter of the wire
m = 8.3 relative units, r = 12 cm, l = 0.6 m
Dependency graph T from d represents a descending curve, in accordance with Figure 16 A. It can be assumed that this is a dependency where n= 1, 2, 3, etc. To check these assumptions, it is necessary to build graphs, etc. Of all such graphs, the most linear is the graph, in accordance with Figure 16 b.
Conclusion. The period of oscillation of a torsion pendulum is inversely proportional to the square of the diameter of the suspension wire. Some scatter of points can be explained by measurement errors of the oscillation period and wire diameter d, as well as random reasons.
The studies carried out allow us to conclude that the period of oscillation of a torsion pendulum should be calculated according to the formula, where k- proportionality coefficient, which also depends on elastic properties suspension material - torsion modulus, shear modulus.
Physics"
Uphysics teacher:
Gorsheneva Natalya Ivanovna
2011
G
The role of experiment in teaching physics.
Already in the definition of physics as a science there is a combination of both theoretical and practical parts. It is very important that in the process of teaching physics, the teacher can demonstrate to his students as fully as possible the interrelation of these parts. After all, when students feel this relationship, they will be able to give a correct theoretical explanation to many processes occurring around them in everyday life, in nature.
Without experiment there is no, and cannot be, rational teaching of physics; one verbal learning physics inevitably leads to formalism and rote learning. The teacher's first thoughts should be aimed at ensuring that the student sees the experiment and does it himself, sees the device in the hands of the teacher and holds it in his own hands.
An educational experiment is a teaching tool in the form of specially organized and conducted experiments by a teacher and a student.
Objectives of the educational experiment:
Solving basic educational tasks;
Formation and development of cognitive and mental activity;
Polytechnic training;
Formation of students' worldview.
Cognitive (learning the basics of science in practice);
Educational (formation of a scientific worldview);
Developmental (develops thinking and skills).
Types of physical experiments.
What forms of practical training can be offered in addition to the teacher's story? First of all, of course, this is the observation by students of demonstrations of experiments carried out by the teacher in the classroom when explaining new material or when repeating what has been covered; it is also possible to offer experiments conducted by the students themselves in the classroom during lessons in the process of frontal laboratory work under the direct supervision of the teacher. You can also offer: 1) experiments conducted by the students themselves in the classroom during a physical workshop; 2) demonstration experiments conducted by students when answering; 3) experiments carried out by students outside of school on the teacher’s homework; 4) observations of short-term and long-term phenomena of nature, technology and everyday life, carried out by students at home on special instructions from the teacher.
What can be said about the above forms of training?
Demonstration experiment is one of the components of an educational physical experiment and is a reproduction of physical phenomena by a teacher on a demonstration table using special instruments. It refers to illustrative empirical methods training. Role demonstration experiment in teaching is determined by the role that experiment plays in physics and science as a source of knowledge and a criterion of its truth, and its capabilities for organizing the educational and cognitive activities of students.
The significance of the demonstration physical experiment is that:
Students get acquainted with the experimental method of knowledge in physics, with the role of experiment in physical research(as a result, they develop a scientific worldview);
Students develop some experimental skills: observe phenomena, put forward hypotheses, plan an experiment, analyze results, establish dependencies between quantities, draw conclusions, etc.
A demonstration experiment, being a means of clarity, helps organize students’ perception of educational material, its understanding and memorization; allows for polytechnic training students; helps to increase interest in studying physics and create motivation to learn. But when a teacher conducts a demonstration experiment, the main activity is performed by the teacher himself and, at best, one or two students; the rest of the students only passively observe the experiment conducted by the teacher and do nothing themselves. with my own hands. Therefore, it is necessary to have independent experiments by students in physics.
Laboratory exercises.
When teaching physics in high school, experimental skills are developed when students themselves assemble installations, carry out measurements of physical quantities, and 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.
Performing independent laboratory work.
Front laboratory work - this is a type of 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. Here a difficulty arises: the school physics classroom does not always have a sufficient number of sets of instruments and equipment to carry out such work. Old equipment becomes unusable, and, unfortunately, not all schools can afford to purchase new ones. And there’s no escaping the time limit. And if something doesn’t work out for one of the teams, some device doesn’t work or something is missing, then they start asking the teacher for help, distracting others from doing laboratory work.
Physical workshops are held in grades 9-11.
Physics workshop carried out with the aim of repeating, deepening, expanding and generalizing the knowledge gained from various topics of the 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. A physical workshop is usually held at the end of the school year, sometimes at the end of the first and second half-years, 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 of necessary equipment, one-hour physical workshops are practiced. 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.
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, plan for completing the work. 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.
What happens if the teacher invites students to perform an experiment or conduct an observation outside of school, that is, at home or on the street? experiments given at home should not require the use of any instruments and significant material costs. These should be experiments with water, air, and objects that are found in every home. Someone may doubt the scientific value of such experiments; of course, it is minimal. But is it bad if a child himself can check a law or phenomenon discovered many years before him? There is no benefit for humanity, but what is it for a child! Experience is a creative task; doing something on your own, the student, whether he wants it or not, will think about how easier it is to carry out the experiment, where he has encountered a similar phenomenon in practice, where else this phenomenon may be useful. What should be noted here is that children learn to distinguish physical experiments from all sorts of tricks, and not confuse one with the other.
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 homemade instruments are used (lever scales, electroscope, etc.);
What does a child need to conduct the experiment at home? First of all, it's probably enough detailed description experience, indicating the necessary items, where it is said in a form accessible to the child what needs to be done and what to pay attention to. In addition, the teacher is required to provide detailed instructions.
Requirements for home experiments. First of all, this is, of course, safety. Since the experiment is carried out by the student at home independently, without the direct control of the teacher, there should not be any chemicals and items that pose a threat to the health of the child and his home environment. The experiment should not require any significant material costs from the student; when conducting the experiment, objects and substances that are found in almost every home should be used: dishes, jars, bottles, water, salt, and so on. An experiment performed at home by schoolchildren should be simple in execution and equipment, but, at the same time, be valuable in the study and understanding of physics in childhood, and be interesting in content. Since the teacher does not have the opportunity to directly control the experiment performed by students at home, the results of the experiment must be formalized accordingly (approximately as is done when performing front-line laboratory work). The results of the experiment carried out by students at home should be discussed and analyzed in class. Students' work should not be a blind imitation of established patterns; they should contain the broadest manifestation own initiative, creativity, searching for something new. Based on the above, we will briefly formulate the requirements for home experimental tasks: requirements:
Safety during carrying out;
Minimum material costs;
Ease of implementation;
Ease of subsequent control by the teacher;
The presence of creative coloring.
The home experiment can be assigned after completing the topic in class. Then the students will see with my own eyes and become convinced of the validity of the theoretically studied law or phenomenon. At the same time, the knowledge obtained theoretically and tested in practice will be quite firmly embedded in their consciousness.
Or vice versa, you can set a home task, and after completing it, explain the phenomenon. Thus, it is possible to create among students problematic situation and go to problem-based learning, which involuntarily gives rise to students’ cognitive interest in the material being studied, provides cognitive activity students during training, leads to the development creative thinking students. In this case, even if schoolchildren cannot explain the phenomenon they saw at home themselves, they will listen with interest to the teacher’s story.
Stages of the experiment:
Justification for setting up the experiment.
Planning and conducting the experiment.
Evaluation of the obtained result.
Formulation and justification of a hypothesis that can be used as the basis for an experiment.
Determining the purpose of the experiment.
Clarification of the conditions necessary to achieve the stated goal of the experiment.
Designing an experiment that includes answering the questions:
what observations to make
what quantities to measure
instruments and materials necessary for conducting experiments
the course of experiments and the sequence of their implementation
choosing a form for recording experiment results
Selection necessary devices and materials
Installation assembly.
Conducting an experiment accompanied by observations, measurements and recording of their results
Mathematical processing of measurement results
Analysis of experimental results, formulation of conclusions
When conducting any experiment, it is necessary to remember the requirements for the experiment.
Requirements for the experiment:
Visibility;
Short term;
Persuasiveness, accessibility, reliability;
Safety.
In addition to the above types of experiments, there are mental, virtual experiments (see Appendix), which are carried out in virtual laboratories and are of great importance in case of lack of equipment.
Psychologists note that complex visual material is remembered better than its description. Therefore, a demonstration of experiments is captured better than a teacher’s story about a physical experiment.
School is the most amazing laboratory, because the future is created in it! And what it will be depends on us, teachers!
I believe that if a teacher in teaching physics uses an experimental method in which students are systematically involved in the search for ways to solve questions and problems, then we can expect that the result of training will be the development of versatile, original thinking, not constrained by narrow frameworks. A is the path to the development of high intellectual activity of students.
Application.
Classification of types of experiments.
Field
(excursions)
Home
School
Mental
Real
Virtual
Depending on quantity and size
Laboratory
Practical
demonstration
By venue
By method of implementation
Depending on the subject
Experiment
