1. The difference between the knowledge structure of physics in senior high school and physics in junior high school;
1, junior high school physics research problems are relatively independent, while senior high school physics has a knowledge system. Did you learn the new high school in the first semester? Chapter 1: force, chapter 2: linear motion, chapter 3: Newton's law of motion, and chapter 4: the balance of objects itself constitutes a dynamic system. The first chapter describes the knowledge of force to prepare for dynamics. The second chapter studies the law of motion of objects from the perspective of kinematics, and finds out the law of the change of motion state of objects-acceleration. Chapter 3 Newton's law of motion further expounds the change of motion state from the mechanical point of view? The reason for the acceleration). The fourth chapter analyzes the law that the motion state of an object does not change the balance of the object.
2. Junior high school physics only introduces some simple knowledge, while senior high school physics pays attention to deeper research. For example, the concepts of speed and average speed are only introduced in junior high school, and the concept of speed is described in senior high school. Speed is a vector, and the change of speed must have acceleration, which can be divided into acceleration and deceleration. Another example is friction. It is difficult to judge its direction in high school. Friction always hinders the relative motion or relative motion trend of objects. Firstly, we should distinguish which plane it is relative to, and secondly, we should use the knowledge of kinematics to judge the relative motion. Or the direction of the relative motion trend, and then we can find the direction of the force. In some problems, we need to use the knowledge of object balance to draw conclusions. For example, there is an object B on the horizontal plane with an object A on it. Now object B is pulled by a horizontal force F, and they just move in a straight line at a uniform speed on the horizontal plane. Find the friction between A and B: Does object A move in a straight line at a uniform speed? Force balance), which is not affected by force in the horizontal direction, so the friction between A and B is zero.
3. Junior high school physics pays attention to qualitative analysis, while senior high school students pay attention to quantitative analysis. Quantitative analysis is more difficult and certainly more accurate than qualitative analysis. For example, for friction, junior high school only talks about the method of increasing or decreasing friction, which is easy to understand. High school should analyze and calculate the magnitude of friction, and the magnitude of static friction is generally determined by the state of the object. Senior high school physics also emphasizes: (1) paying attention to the analysis of physical processes: understanding the process of physical events and distinguishing which physical quantities remain unchanged and which physical quantities have changed in this process. In particular, more than two physical processes should be analyzed clearly. It is easy to make mistakes if the changes of process and physical quantity are not clearly analyzed. (2) Pay attention to the use of images: Image method is a new method to analyze problems, and its biggest feature is intuition, which is very helpful for us to deal with problems. But it is easy to be confused. For example, displacement images and velocity images are easily confused, and students often feel headaches. In fact, as long as the physical quantities of the ordinate are clearly distinguished and combined with the changing law of kinematics, it is easier to master. (3) Pay attention to the cultivation of experimental ability and skills: Physics experiments in senior high schools are divided into demonstration experiments and student experiments, which play an important role in learning and consolidating our knowledge. Therefore, students are required to carefully observe the demonstration experiment, do a good job in students' experiments, strengthen the exercise of hands-on ability, and pay attention to the analysis of problems in the experiment process.
2. The reasons for the physical steps between junior high school and senior high school:
After graduating from junior high school, students are promoted to senior one. Generally speaking, physics is difficult to learn and teachers find it difficult to teach. This disjointed phenomenon in physics teaching in junior and senior high schools is called steps. According to the different characteristics of the knowledge structure of high school physics and junior high school physics, after analysis, the main reasons for the steps are as follows:
1, the leap from quality to quantity is the first reason.
Physics teaching in junior high school focuses on qualitative analysis of many physical problems, even if quantitative calculation is carried out, it is generally simple; However, in high school physics teaching, most physics problems are not only qualitative analysis, but also a lot of quite complicated quantitative calculations. Students can't adapt to this leap from quality to quantity.
2. The leap from thinking in images to abstract thinking is the second reason.
Physics teaching in junior high school is basically based on thinking in images, based on vivid natural phenomena and intuitive experiments, so that students can acquire knowledge through thinking in images. Most problems in junior high school physics are tangible. After entering high school, physics teaching has moved from image thinking to abstract thinking. Judging from the current textbooks, this step is relatively high. For example, the direction of static friction, instantaneous speed, force analysis of objects, composition and decomposition of forces in physics textbooks for senior one require students to have strong thinking ability. Judging from the cognitive process of human beings, from thinking in images to abstract thinking is a great leap in cognitive ability.
3. The third reason is the transition from single-factor simple logical thinking to multi-factor complex logical thinking (including judgment, reasoning, hypothesis, induction, analysis and deduction, etc.). ).
Junior high school students generally can't solve problems after entering the first year of high school, or just confuse the formula and do things blindly. One of the important reasons is the lack of complex logical thinking ability. I am not good at judging and reasoning, I can't associate, and I lack the ability of analysis, induction and deduction. At this point, there are also great individual differences among students.
4. The fourth reason is the change from simple arithmetic and algebra methods to the comprehensive application of functions, images, vector operations, extreme values and other mathematical tools to solve physical problems.
Using mathematical tools to solve physical problems is not prominent in junior high school physics teaching, but it has become a vital means to deal with various practical problems in senior high school physics teaching. In particular, the concept and operation of vectors in senior high school physics are very strange and difficult for junior high school students. It takes a process to establish this concept and master its operation. If we consider the fact that there is an obvious gap between the application of individual mathematical tools and the mathematical knowledge actually mastered by students. Then, this step is even more prominent.
5. The inadaptability of learning methods is the fifth reason.
Junior high school students are more accustomed to being taught knowledge by teachers, while high school physics learning requires students to acquire knowledge independently or actively under the guidance of teachers (including independent preview, observation and summary of experiments, systematic reading of textbooks and arrangement of knowledge, etc.). In addition, understanding and memory are becoming more and more important in senior high school physics learning. Many students also need an adaptation process to adapt to this change in learning methods.
3. How to learn physics well in senior high school
Physics is a natural science course that is difficult to learn. You can't learn by rote. If you recite word for word, you can't do a problem. Physics is taught in junior high schools, senior high schools and universities respectively. There are many qualitative things in junior high school, many quantitative things in senior high school and more quantitative things in universities, and we must use advanced mathematics to calculate them. So, how to learn physics well?
In school, we see students who study well, students who study well in all subjects, and students who study poorly in all subjects, which are basically the same. In addition to the innate factors of small probability, there is indeed a problem of learning methods here.
Who doesn't want to be a good student, but if you want to be a really good student, the first thing is to study hard, that is, to dare to endure hardships, cherish time and study tirelessly. Establish confidence, firmly believe that you can learn any course well, firmly believe in the "law of conservation of energy transformation", and firmly believe that you should get a little if you pay a little. Please read the following two quotations about this article: I never believe in any innate or acquired talent, and I can succeed without firm and long-term efforts-Dickens (English writer); The main reason why some people can go far beyond others is not so much genius as his indomitable spirit of concentrating on his studies and not giving up until he reaches his goal. -Dalton (British chemist).
The first item mentioned above should be said to be the problem of learning attitude and thinking method. The second is to understand that there are seven links in learning as a student: preview before class → concentrate in class → review in time → work independently → solve problems → systematically summarize → study after class. In the above seven links, there are many learning methods. According to the characteristics of physics and the problem of "how to learn physics well", some concrete learning methods are put forward:
(1) preview before class. It is to preview the contents of the textbook to be learned the next day the night before class, and to understand the knowledge, difficulties and doubts through reading before class, so as to listen to the class purposefully and improve the learning efficiency. Through pre-class preparation, we can also cultivate self-study ability and self-study habits.
(2) concentrate on class. Listen carefully in class and don't be distracted. Don't be self-righteous, ask the teacher modestly, and don't give up listening just because the teacher speaks simply. If this happens, it can be regarded as review and consolidation. Try to be consistent and synchronized with the teacher, and you can't do it yourself, otherwise it will be self-study. On the other hand, we should also pay attention to learning teachers' ideas and methods of analyzing and solving problems and improve our thinking ability. Class is mainly based on listening, and there are notebooks, and some things should be written down. Knowledge structure, good problem-solving methods, good examples, places you don't understand, etc. Should be recorded. After class, you should organize your notes. On the one hand, you should "digest" and on the other hand, you should supplement your notes. Notebook is not only to remember what the teacher said in class, but also to make some reading notes. Good problems found in homework and good solutions should also be recorded in a notebook, which is what students often call a "good problem book". Hard-won notebooks should be numbered, read them often in the future, and keep them if you can put them down.
(3) Review in time. We should review and consolidate what we have learned in time. After class, you must review the whole process of introduction, analysis, generalization, summary and application of the new knowledge you have just learned, and compare it with similar old knowledge in your brain to see if there is any contradiction. If there is a contradiction, it means that we have not really understood it. At this time, we need to rethink and study again. On the basis of knowing what you have learned, finish your homework in time. Students who have the ability can do some extracurricular exercises in moderation to test the accuracy of mastering knowledge and consolidate what they have learned.
(4) Do the problem independently. We should complete some problems independently with good quality and quantity (meaning not relying on others). There must be a certain number of topics, not too few, but also a certain quality, that is to say, there must be some difficulty. Anyone who studies mathematics and physics can't learn this level well. Solving problems independently may sometimes be slower, sometimes detours, sometimes even impossible, but these are normal and the only way for any beginner to succeed. In addition, there are five requirements for completing homework: ① neat handwriting; (2) Drawing specifications; ③ Express clearly; ④ Strict reasoning; ⑤ Accurate calculation. After the homework is corrected and distributed, the mistakes should be carefully corrected and bound into a book for future review.
(5) solve the problem. If you have any problems or mistakes, you should write them down in a special notebook, and then solve them by reflection or consulting teachers and classmates. The special book is named "Record Book of Difficult Problems", and it needs to be changed after recording, and each book should be kept by number.
(6) system summary. After each lesson, we should connect the knowledge points scattered in each chapter into a line, pave a surface and form a network, so that the knowledge we have learned can be systematic, regular and structured, so that we can use it freely and think actively. We should attach importance to the knowledge structure, master it systematically, and systematize scattered knowledge. From the whole knowledge structure of physics to the knowledge structure of mechanics, even to chapters, such as the knowledge structure of statics and so on.
(7) Extracurricular study. Read a proper amount of extra-curricular books to enrich your knowledge and broaden your horizons. Practice shows that students with excellent physics scores have read appropriate extracurricular books. This is because different books and different authors will explain the problem in different ways from different angles. Readers can deepen their understanding of physical concepts and laws from all aspects and learn many ingenious and simple ideas and methods to solve problems. If you know more, your mind will surely live.
In short, there are roughly six levels in learning physics, namely, understanding first, remembering later, practicing, gradually mastering, practice makes perfect, and being brave in innovation, so as to finally reach the highest level of learning physics.
(2) Physics, a natural science course, is difficult to learn. You can't learn by rote. You can recite it word for word, but you still can't do the problem. Let's talk about physics in junior high school, senior high school and university. There are many qualitative things in junior high school, quantitative things in senior high school and quantitative things in universities, which need to be calculated by advanced mathematics. So, how to learn physics well?
If you want to learn physics well, you should not only learn physics well, but also learn mathematics, chemistry, Chinese, history and other courses well. In other words, you can learn what you have learned. In fact, in school, the students we meet who learn well do well in all subjects, and the students who learn poorly do poorly in all subjects. This is basically a question of learning methods, except for the innate factors of small probability.
Who doesn't want to be a good student, but to be a really good student, the first thing is to study hard, that is, to dare to endure hardships, cherish time and study tirelessly. Establish confidence, firmly believe that you can learn any course well, firmly believe in the "law of conservation of energy transformation", and firmly believe that if you make a contribution, you should gain something.
Please read the following three quotations about this article:
I never believe in any innate or acquired talent, and I can succeed without firm and long-term efforts.
-Dickens (English writer)
The main reason why some people can go far beyond others is not so much genius as his indomitable spirit of concentrating on his studies and not giving up until he reaches his goal.
-Dalton (British chemist)
The fastest and slowest, longest and shortest, most common and most precious, most easily overlooked and most regrettable thing in the world is time.
-Gorky (Soviet writer)
The first item mentioned above should be said to be the problem of learning attitude and thinking method.
The second is to understand that there are eight links in learning as a student: making a plan → previewing before class → concentrating in class → reviewing in time → independent homework → solving problems → systematic summary → extracurricular learning. The most important thing here is: concentrate in class → review in time → independent homework → problem solving → systematic summary, these five links. There are many learning methods in the above eight links, and the following is for physics.
(1) Sanji. Basic concepts should be clear, basic laws should be familiar, and basic methods should be mastered. About basic concepts, such as speed, it has two meanings: one is to express the size of speed; The second is the ratio of distance to time (for example, in uniform circular motion), while speed is the ratio of displacement to time (for example, in uniform linear motion). Taking the basic law as an example, there are two formulas for calculating the average speed, V = S/T and V = (VO+VT)/2. The former is a definition, which is applicable to any situation, while the latter is a deduction, which is only applicable to the situation of doing uniform linear motion. For example, holism and isolationism, which are often used in studying middle school problems, are typical complementary methods. Finally, a question belongs to three basic problems. That is, in the process of learning physics, we sum up some concise and practical inferences or conclusions, which are very useful for solving problems and learning physics well. For example, "the potential decreases along the electric field line"; "The tension on the same rope is equal"; "Maximum speed when acceleration is zero"; "Lorentz force does not do work" and so on.
(2) Do the problem independently. Do some problems independently with good quality and quantity (meaning not relying on others). There should be a certain number of questions, not too few, but also a certain quality, that is to say, it is difficult. Anyone who studies math and physics can't learn it well. Solving problems independently may sometimes be slower, sometimes detours, and sometimes even impossible, but these are normal and none of them.
(3) Physical process. It is necessary to clarify the physical process. If the physical process is unclear, there will be hidden dangers in solving problems. No matter how difficult the topic is, try to draw as many pictures as possible, some are just sketches, and some need to draw accurate pictures, using compasses, triangles, protractors and so on. To represent geometric relationships.
Drawing can turn abstract thinking into image thinking and grasp the physical process more accurately. With drawing, we can make state analysis and dynamic analysis. State analysis is fixed, dead and discontinuous, while dynamic analysis is alive and continuous.
Class. Listen carefully in class and don't think or think as little as possible. Don't be self-righteous, learn from the teacher modestly. Don't give up listening just because the teacher speaks simply. If this happens, it can be regarded as review and consolidation. Try to be consistent and synchronized with the teacher, you can't do it yourself. Otherwise, it is tantamount to self-study. After getting started, you are allowed to have certain activities.
(5) notebook. Class is mainly about listening to lectures, and you should have a notebook. Some things should be written down. Knowledge structure, good problem-solving methods, good examples, places that I don't understand well, and so on. After class, you should also sort out your notes, on the one hand, for "digestion", on the other hand, you should also supplement your notes. Notebooks should not only record what the teacher said in class, but also make some reading notes you found in your homework. It is what students often call a "good textbook". Hard-made notebooks should be numbered, studied in the future and preserved for life.
(6) learning materials. Learning materials should be well preserved, classified and marked. The classification of learning materials includes exercises, test papers and experimental reports. Correcting means, for example, exercises, good questions, valuable questions and error-prone questions are not corrected, but corrected separately for future reading, which can save a lot of time.
(7) time. Time is precious. Without time, it is too late to do anything, so we should pay attention to making full use of time, which is a very superb art. For example, we can save time by using the learning method of "recalling". Before going to bed, waiting for the bus and walking on the road, you can recall the lessons of the day one by one, so that you can learn them again and again to achieve the purpose of strengthening. You may think of some problems when you walk. People who study physics often have several problems in their minds that they can't do, and they never forget them. I don't know when they will make a breakthrough and find the answer to the question.
(8) learn from others. Learn from others with an open mind, from classmates, from people around you, and see how others learn. I often have "academic" exchanges with them, teach and learn from each other, and never be self-righteous. Don't be conservative. Tell others when you have a good method, so that others will tell you when you have a good method. I have several good friends in my studies.
(9) Knowledge structure. We should pay attention to the knowledge structure and master it systematically, so that scattered knowledge can be systematized, from the whole physical knowledge structure to the mechanical knowledge structure, and even to chapters, such as the knowledge structure of statics.
(10) Mathematics. The calculation of physics depends on mathematics, which is too important for learning physics. Physics is difficult to do without mathematics as a calculation tool. In the physics department of a university, mathematics and physics are equally important. To learn math well, make good use of this powerful tool.