Образования
Materials and methods of research
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| Materials and methods of research. Physics is an experimental science. Therefore, the educational experiment in physics is a source of knowledge of students in physics and a method of studying physical phenomena, the main visual aid in physics lessons. A demonstration of physical processes with the help of special devices and the observation of the students themselves for what they do, study and control is called a physical educational experiment. Depending on the organizational form, the system of educational experiment in physics consists of 6 types:
1) demonstration experiment; 2) laboratory experiment; 3) a physical workshop; 4) experiment outside the classroom and school; 5) solving experimental problems; 6) manufacture of home-made physical devices and exhibition device A demonstration is a teacher's demonstration of physical phenomena and the connection between them, designed for simultaneous perception by all students in the class. Demonstration experiments are able to create physical concepts and form physical concepts: they specify the teacher's analysis when submitting new material, make it clear and convincing, and also arouse students ' interest in the subject. The demonstration experiment or experiments are shown in the lesson, so it is considered part of the lesson and is used in conjunction with other teaching methods (conversation, lecture, problem presentation). Therefore, physics lessons cannot be conducted qualitatively until demonstration experiments are shown, which we must understand, for example, as an analogy with explaining to a blind person the different colors of the light spectrum. Physical experiments in the classroom are often demonstrated by the teacher, sometimes they can be performedby the students themselves. The methodological value of a physical demonstration experiment requires the teacher to meet the following conditions: The experience should be expressed in direct organic contact with the learning material being studied (for example, fluid pressure) The demonstration experiment should have a clear goal (for example, what is the value of the buoyant force, Archimedes’ principle?) The physical experience shown in the lesson should not take much time and should not show all the devices at once. It is most effective to use only the main ones in the explanation of the topic, and use the rest in the lessons of surveys, repetitions of students; It is desirable that physical experiments should be mainly intended to prove the quantitative significance of physical laws (Newton's second law), while the demonstration of their qualitative side is less common(light dispersion). From several options of experience, it follows that when explaining a new lesson, the most obvious of them, the most powerful effect (inertia, pressure transfer) should be indicated) When demonstrating the experiment, only the necessary devices should be displayed on the demonstration table. Drawings and diagrams related to the specified experience should be drawn on the board in a timely manner. Ideally-dynamically draw a picture. For a productive demonstration of a physical experiment, the methodical skills of a physics teacher are necessary, which must be given an appropriate explanation and conclusion. I present to your attention the demo work below Demonstration experiment: Pendulum resonance Instrumentation:
According to Fig. 1, install the equipment, fix it on the table with a clamp. The practice is carried out in the following sequence. Pulling by hand from the center of the thread leads to vibrations with a smaller amplitude. Corresponds to the oscillation frequency of the same as the natural oscillation frequency of one of the pendulums. While other pendulums are oscillating, the amplitude of the selected pendulum begins to gradually increase. Fig. 1. Installation for demonstrating the resonance of pendulums Changing the frequency of vibrations of the thread, conduct the specified experiment in alternation with each of the pendulums and explain the essence of the phenomenon. All pendulums are stopped, and 1 pendulum is set in oscillation and (it serves as a vibrator) we control what state the other pendulums are in. From everything you can see that the 4 pendulums swing more strongly, with the same frequency as the vibrator. Repeat the experiment, shortening the length of the pendulum 1 to 75 cm. Now it leads to the resonance of 3 pendulums. Finally, it shortens the length of the pendulum 1 to 50 cm and demonstrates the resonance of the pendulum 2. Pendulums 2,3and 4 are used as vibrators, and pendulum 1 as a resonator. Gradually changing the length of the pendulum 1, it is possible to reflect the phenomenon of resonance of each pendulum, i.e. to demonstrate the resonator, alternating it with the frequency of vibrators. Draw students' attention to the phase difference between the vibrations of the vibrator and the resonator. At the moment of resonance, it is equal to 900, which is very clearly seen in practice due to the slow oscillations of the pendulums. Of great importance in carrying out the described experiments is the magnitude of the connection between the pendulums. The thread between them must be very free, so that the energy is transferred from the vibrator to the resonator in only one direction. When the bond is strong, there is an energy exchange between the pendulums, and the resonance phenomenon is complicated by shocks. жүктеу/скачать 2,01 Mb. Достарыңызбен бөлісу:
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