Do enough physical experiments.
The Physics Teaching Syllabus of Nine-year Compulsory Education points out: "Demonstrations and students' experiments can make students get a concrete and clear understanding of physical facts, which is the necessary basis for understanding physical concepts and laws. ..... Observation experiment plays an irreplaceable role in cultivating students' observation and experiment ability, seeking truth from facts, and stimulating their interest in learning. " In recent years, because the majority of physics teachers are more deeply aware of the basic position and important role of experimental teaching, they actively and try their best to carry out experimental teaching, and the teaching effect has been greatly improved. With the deepening of physics teaching reform, the proportion of experiments in physics classroom will become larger and larger, and the experimental forms will be constantly renovated. The existing experimental instruments in the school may not keep up with the demand. Physics teachers can't wait passively. They should adjust measures to local conditions, simplify the complex or find alternative experimental methods to keep the strong original atmosphere of physics class. As for completely losing the original taste of physics, the practice of replacing physics experiments with "experiments" on the blackboard can not achieve the purpose of quality education and should be completely abandoned. In addition, in view of the current situation that middle school students have few experiments in groups, physics teachers should try to turn demonstration experiments into classroom students' experiments. Doing and learning in this way not only increases the original flavor of physics class, but also helps teachers and students to cooperate to find the law, students actively exercise their ability and improve the efficiency of classroom teaching.
Improve the success rate of physical experiments
The success rate of physics experiment is a sign to measure the taste quality of physics teaching materials. If the experiment fails, it will lead to the deterioration or loss of the original taste and reduce the students' enthusiasm for learning. In order to ensure the high success rate of physics demonstration experiments, teachers should make good preparations before class: 1) read the instruction manual of the instrument carefully, understand the main structure and basic principle of the instrument, do more experiments before class, and deal with problems in time when found; 2) estimate and master the experimental time; 3) Understand the accuracy of the experiment, find out the main causes of errors and the methods to reduce them; 4) How to guide students to observe the experiment effectively (and draw up experimental thinking questions) in the process of conceiving the demonstration experiment.
In order to ensure the high success rate of students' grouping experiments, teachers should do experiments in person before class to study three aspects: 1) whether the performance of experimental devices and instruments meets the requirements of the specification, and what debugging and improvement are needed; 2) Grasp the essentials of operation specification, find the difficulties, determine how to make the operation demonstration in place, and explain it clearly in class; 3) Measure more accurate data according to the specification requirements, calculate the results, and then determine the appropriate error range as the reference value of the experimental results that the performance of the instruments used may reach, and tell the students in class: "The experimental results are within this error range, and the experiment is successful." Practice has proved that after giving such a reference value, students are particularly serious in doing experiments and are particularly happy to succeed. On the other hand, students are not sure whether the measurement is accurate and can operate at will, which will make the education of cultivating serious scientific attitude fail and greatly affect the original taste of physics class.
Improving and optimizing physical experiments
Perhaps some physics teachers think that the experiments in textbooks have been examined and approved by many educational experts, so long as the experiments are done according to the textbooks, there is no need to improve and optimize them at all. Actually, it is not. Not all the experiments in teaching materials are perfect, and some experiments have some shortcomings or defects in materials, principles, steps and credibility, which need to be improved and optimized by teachers in teaching.
For example, there is a demonstration experiment of solid deformation in middle school physics textbooks: squeeze a cylindrical glass bottle filled with water by hand (open the center of the bottle cap and insert a glass tube), and the water level in the glass tube rises; Release your hand, and the water surface will fall back to its original position, indicating that the bottle has been squeezed and deformed. For this experiment, some students suggested that the water surface rose not because of the deformation of the bottle, but because of the high temperature of the hand, which led to the heat absorption and volume expansion of the water in the bottle. In order to eliminate students' misunderstanding, the cylindrical glass bottle can be replaced by an elliptical cylindrical glass bottle, and the water level in the thin tube will rise after being squeezed along the short axis. After squeezing along the long axis of the glass bottle, the water level in the thin tube not only does not rise, but falls, thus making students believe that the rise and fall of the water level is the result of the deformation of the glass bottle. Such a small improvement greatly increased the credibility of the experiment. It can be seen that improving and optimizing physics experiments can not only enrich the original taste of physics classes, but also improve the quality of physics teaching.
Change some demonstration experiments into exploratory group experiments to cultivate students' innovative ability.
Traditional classroom demonstration experiments are generally led by teachers, and students are just bystanders, which is not conducive to the cultivation of students' innovative ability. If the experimental conditions permit, some demonstration experiments can be changed to exploratory grouping experiments. For example, in the teaching of what factors are related to sliding friction, students are guided to guess according to their own life experience, and then it is proposed that: 1) sliding friction may be related to pressure; 2) Sliding friction may be related to the roughness of the contact surface; 3) Sliding friction may be related to the size of contact surface. The experimental method of controlling conditions is adopted to guide students to design experiments and choose experimental equipment from the above experimental purposes and experiments.
Teachers and students work together to carry out the experiment, record the magnitude of the pulling force, and draw a conclusion by analyzing and processing the experimental data. In this new teaching mode of "guidance-exploration-experiment-mastery", the educational concept of "for the development of every student" is fully embodied, so that students can carry out independent experiments, experience learning independently and learn with problems and unique personality under the creative guidance of teachers.
(Author: Gushu Town Middle School, yutian county, Hebei)