How to carry out inquiry learning?

The traditional physics classroom teaching mode is mostly indoctrination-acceptance. Teachers pay attention to imparting knowledge and conclusions to students accurately, and most students are in a passive acceptance state. In the indoctrination-acceptance teaching method, students often don't feel the fun of learning and exploration, and it is difficult to generate lasting interest in learning and can't adapt to the new learning requirements. In physics teaching in senior high school, it is the goal advocated by the new curriculum and the need of students' lifelong learning and healthy development to guide students to master the basic methods of scientific inquiry, cultivate their interest in inquiry learning, develop their ability of autonomous learning, and cultivate their scientific attitude of seeking truth from facts and sense of responsibility for caring for society. First, the way of physics inquiry learning activities There are various ways to carry out physics inquiry learning activities in senior high schools, which can be divided into the following four types according to the content of the activities. 1. The basic process of exploring physical laws is to find some problems by observing experimental phenomena or applying known laws and theories to logically reason a phenomenon, then design experiments, collect experimental data, analyze and summarize the experimental data, and finally draw regular conclusions. For example, students in Grade One and Grade Two can explore such small topics as: using sensors to explore the factors affecting friction, exploring which factors are related to the period of a simple pendulum, exploring the energy problem in collision, what laws light follows when refracting at the interface, how to find circuit faults, and the relationship between the period of a spring oscillator on an air cushion and its mass and stiffness. 2. Inquiry activities focusing on discovering the basic principles of daily-use instruments and articles Students often observe some interesting phenomena or articles in their daily lives and are interested in the basic principles of these phenomena or articles. After students ask questions, teachers lead students to explore its basic principles by consulting materials, disassembling instruments and supplies, or taking instruments and supplies to the laboratory for measurement. Such as the working principle of bicycle electric light, toilet flushing device, car speedometer and household water-saving device, etc., often arouse students' interest in inquiry. 3. Based on experiments and hands-on inquiry activities, we design some interesting experiments every year in Science and Technology Month. Some of the contents of these experiments are transplanted into extracurricular books, some are learned from various practical activities, and some are designed and made by themselves according to what they have learned. For example, how to use the geomagnetic field to obtain the induced current, assemble a simple telescope, kaleidoscope and a ball moving in the opposite direction, and assemble a simple electrostatic copier to make a "magic pendulum". 4. Inquiry activities focusing on measuring basic physical quantities Although some physical quantities are not given in textbooks, their measurement methods contain many important physical ideas and important research methods. Therefore, measuring basic physical quantities can be used as a content of inquiry activities. For example, various methods can be used to measure the magnetic induction intensity and current around the magnet, the frequency of sound waves, the strobe frequency of fluorescent lamps, the maximum and minimum resistances, and so on. Second, the key links of inquiry learning activities Every inquiry learning activity has many links, especially the following links are very critical. 1. Determining a good topic is a good start to carry out inquiry learning activities. Many of the topics raised by students are vague, superficial, or too broad and profound, and the knowledge involved may be very wide and deep, which is often difficult to solve with their existing knowledge base. At this time, teachers need to guide students from the significance, operation methods, content and other aspects of the topic, gradually narrow the scope of the topic, clarify the research purpose of the topic, and finally determine the content of the topic. For example, it is difficult for students to make an energy-saving generator at the beginning of the course "Principles of Bicycle Electric Lights". We need to analyze several problems together: (1) Is there a specific plan? (2) Do you know the power generation principle of the generator? (3) What basic physical knowledge does the generator involve? (4) From which angle can we save energy? After asking questions, the teacher took the students to the laboratory to see the hand-cranked generator. Then assign tasks: (1) Investigate which equipment is equipped with generators? (2) Understand the basic principles of these generators. Students found devices that can generate electricity, such as rechargeable batteries on electric bicycles and motorcycle lights. After careful study, considering the knowledge involved in generators and the knowledge base of students, they finally decided on a more feasible topic-studying the basic principle of bicycle lights. The students took apart the bought bicycle lights and found many unexpected situations, such as the magnetic poles of magnets are not N and S, the cutting magnetic induction line of coils is not as simple as that drawn in the book, and the connection mode and current waveform are very complicated. So, the students came up with various methods to measure the direction and intensity of the magnetic field in the motorcycle lamp, draw the waveform of the current, and finally figure out the principle of the motorcycle lamp and draw the schematic diagram of the motorcycle lamp. In the actual operation process, students learned a lot of knowledge, such as the use of sensors, multimeters and oscilloscopes. In addition, there are many unexpected discoveries. For example, when a classmate showed the magnetic pole shape of a magnet with iron filings, he found that the magnet of a motorcycle lamp was very special, with eight magnetic poles. In short, the topic selection has a process from large to small, from infeasible to feasible, and grasping this link is the key to completing the inquiry activity. 2. After the theme of experimental design and operation inquiry activity is determined, the operation must be implemented. There are many factors to consider in this link, which are also very important. To sum up, there are the following aspects: (1) What instruments are needed for a physical experiment? (2) How to ensure the experimental conditions? (3) What factors are independent variables? (4) How to control variables and measure them? (5) What instrument is used for measurement? (6) What problems should be paid attention to when using the instrument? (7) What items are needed to record data in the table? For example, exploring the laws of collisions. The purpose of this experiment is to explore what laws restrict the collision process besides the conservation of momentum. Experimental device (prepared by the teacher): air cushion guide rail, slider, photoelectric timer, mathematical experimental instrument (sensor), computer, etc. Physical process (students discuss and analyze): let two sliders collide, and then measure the instantaneous speed and mass of the sliders before and after the collision to find out the law. Control of experimental variables (students discuss, try and summarize in groups, and different groups may do different things, resulting in three kinds of ***9 situations): ① There is a spring coil between two sliders, which makes the spring coil elastically deform during the collision, and the quality control of two sliders is three situations; ; . (2) There is plasticine between the two sliders, which makes plasticine plastically deform during the collision, and the quality of the two sliders is also controlled under three conditions. ; . (3) There are adhesive buttons between the two sliders, which make the two sliders move together after collision, and the quality of the two sliders is also controlled in three situations. ; . Guarantee of experimental conditions (through students' pre-experimental analysis and summary of trying work): Students draw five conclusions. Many problems in the above experiments should be summarized by students in the experiments and solved step by step. In the process of design and operation, students' thinking ability and experimental ability are exercised and improved. 3. The processing and analysis of experimental data should first have a scientific attitude of respecting facts. When students experiment, sometimes the experimental results are different from expectations, which will make them waver, doubt that their experiments are inaccurate, and want to correct or supplement the figures. This is a practice that does not respect the experimental facts. We should carefully analyze the experimental conditions and process to see if it really meets the needs of the experimental principle, and also carefully consult the data to see if the results of this experiment have been explained by predecessors. In addition, it should be noted that the conclusions of physical laws can be not only given from experimental conclusions, but also deduced from theory. The process of physicists exploring the laws of physics is full of hardships and has gone through many tortuous roads, during which many sparks of rational thinking flashed. Don't think that a simple experiment will produce a great theory. For example, in the experiment of refraction law, the students in the inquiry group made several sets of measurements on water, glass and other media, and obtained several sets of experimental data (table 1 is a set of experimental data for students). When analyzing these experimental data, the teacher met an unexpected problem. Table 1 experimental refraction angle law sin/sinlg/LG1071.421.1820131.521. Some students think that equal proportion is equal to a constant, while others have different views. Which conclusion should it be? At this time, students should be guided to understand what it means to take logarithm. Logarithm is equivalent to reducing this number many times. Then take the ratio to make the original gap smaller. The original difference between incident angle and refraction angle is less than one order of magnitude. After taking the logarithm, the gap is smaller, and the order of magnitude is smaller than it. Therefore, it is not omnipotent to find a relationship by logarithm, it depends on the specific situation. Then guide students to make theoretical analysis. According to the principle of shortest optical path (also called Fermat's principle), students can be guided to derive constants, but they can't get constants. In addition, taking the sine value of the angle has clear geometric and physical significance, but taking the logarithm of the angle is meaningless. Third, the effect is 1. Students' autonomy is realized through inquiry learning activities. The core idea of constructivism theory is that knowledge should not be passively accepted, but should be actively constructed by cognitive subjects. In inquiry teaching activities, the role of teachers is to guide and advise students, from imparting knowledge to promoting students' development. Teachers have changed from "protagonists" to "protagonists in equality". Students decide what to learn and how to learn, and the research results are summarized by students themselves. Finally, they should show and explain in front of the whole class, and then ask the teacher for help when they encounter difficulties. In the meantime, students should complete their studies through communication, discussion, consulting materials, designing and implementing experiments, revising and other activities, instead of simply teaching by teachers and learning by students; For students, it embodies the subjectivity of learning and has the opportunity to show their personality. The student-centered inquiry learning under the guidance of teachers gives students space and opportunities for self-development and self-display, and students have a strong interest in learning and high participation in activities. 2. Research-based learning activities promote students' understanding of science and improve their innovative consciousness and research ability. Inquiry activities enable students to return to the refining process and application process of physical concepts and laws, and cause students to conduct empirical investigations. By experimenting, collecting and using data, they can form explanations of scientific phenomena, which is conducive to deepening the understanding of physical theory, combining physical theory with practice, and generating lasting interest in physics learning. A special physics teacher once pointed out: "To learn physics well, you can't just rely on lectures and homework. You must have a lot of reading and' research', which is the key to learning physics as a whole. " "Research" here refers to inquiry learning activities. He encourages students to do more challenging projects in high school. 3. Through inquiry learning activities, students' sense of unity and cooperation and communication skills have been improved. From the initial topic selection, to designing research plans, collecting data, consulting research materials, making questionnaires and writing research reports, and finally demonstrating and explaining in groups of 3-5 people. There is division of labor, cooperation, discussion and communication in the group. Each member should undertake the tasks assigned to him, communicate with each other and integrate everyone's research into a whole. To form mutual trust among members in the group, if there is conflict in the group, we must find ways to solve the conflict. In this process, students will experience setbacks and successes and feel equality and justice. After several years of follow-up, we found that students' cooperative consciousness and communication ability have been greatly improved, and most of the inquiry learning activity groups established shortly after entering senior one have maintained good cooperative relations for three years. Fourth, think about 1. Topics should be selected, not all of which are suitable for students to carry out inquiry learning, such as ohm's law. Someone designed such an inquiry experiment-keeping the resistance constant, changing the voltage at both ends of the conductor, thus changing the current in the circuit, measuring a set of values with voltmeter and ammeter, and drawing the conclusion that the current is proportional to the voltage from the values. This design, at first glance, allows students to explore Ohm's law, but in fact there are logical problems, because both ammeter and voltmeter work according to Ohm's law. Using this table to measure shows that ohm's law has been recognized, and using it to find the law will make the mistake of circular argument. Historically, it is not easy to get ohm's law. At that time, ammeters and voltmeters had not been invented. Ohm uses the deflection direction of the magnetic needle to indicate the current, because the magnetic needle is affected by the geomagnetic field and the current magnetic field, and the N pole is in the direction of the combined magnetic field. The deflection direction of the pointer is different with different current. The temperature difference of thermocouple is used to represent the characteristics of power supply, and copper wires with different lengths are used to reflect the characteristics of conductor. These are all very ingenious methods and ideas at that time. 2. Teachers' guidance on inquiry learning activities requires students to study inquiry topics, which will encounter many difficulties, such as weak knowledge base and poor operability of some topics. Therefore, teachers' guidance and suggestions are very important in this inquiry learning activity. First of all, students are often not necessarily interested in the contents of textbooks, nor are they necessarily interested in the professional knowledge of teachers. It is likely to be brand-new for teachers, and teachers should pay attention to learning and accumulation to adapt to the new requirements. Secondly, we should be cautious about how to guide students. Since it is an inquiry learning activity, the key lies in inquiry. Even if teachers need guidance, teachers can't directly hand over their own conclusions and checked materials to students. They should design some questions to guide students to think and point out learning methods. In short, in inquiry learning activities, students can find problems independently, and through consulting materials, experiments, operations, surveys, information search and processing, expression and communication, they can achieve the purpose of experiencing the inquiry process, acquiring knowledge and ability, mastering problem-solving methods and gaining emotional experience.