Junior High School Physics Summary Problem Solving Skills 36 Problem Solving Skills for Junior High

There is no difficulty in junior high school physics, the key is 3 points, 1 The most important thing is to understand, many people learn physics can not understand the principles of physics or the deep connotation, some are memorized (except for physical formulas), it is difficult to apply the problem when doing this, and you can't think of relevant knowledge when you see the topic!

2 is the mastery of the question type, the topic generally has a "mother", often usually done homework after class, the disintegration method is roughly the same to change the soup without changing the medicine, the most important thing in physics is the understanding of the question type, the analysis process is the most important! Therefore, on the basis of 1, you must do more questions to consolidate your problem-solving ideas and thinking methods! Some people always want to set formulas when writing physics problems, and some can't even analyze them.

3. The knowledge should be extensive, and the examples, experiments, and knowledge in the book must be read more, especially the experiment is the most important, and most of the physics questions are experiments and models!

This is my experience in physics, and I hope you can use it.

I usually do the question. No, you can ask me.

The techniques for solving physics questions in junior high school are as follows:

1. Techniques for judging whether an object is electrified.

If two objects are attracted to each other. Then there are two types of electrified objects.

1) All are charged and have a heterogeneous charge.

2) One is charged and the other is not charged.

3) If two objects repel each other. Then the electrification of the object is; Both are charged and have the same charge.

2. The skill of judging the rheostat connected to the circuit part.

1) If it is a structural diagram, the part between the slide and the lower binding post is the part connected to the circuit.

2) In the case of a circuit symbol diagram, the part through which the current flows is the part that is connected to the circuit.

3. Skill of judging the measured values of series and parallel circuits and voltmeters and ammeters.

1) Remove the voltmeter first, and regard the code oasil meter as a wire.

2) There are several current paths in the circuit, if there is only one path, it is in series; Otherwise it is parallel.

3) Starting from the positive pole of the power supply, see who the ammeter is connected with in series, and it will measure the current value of whom; When looking at who the voltmeter is connected to in parallel, it measures whose voltage values are at both ends.

Difficulty

When the object is placed outside the focal point, it becomes an inverted real image on the other side of the convex lens, and there are three types of real images: reduced, equal size, and magnified. The smaller the object distance, the larger the image distance, and the larger the real image. The object is placed in focus, and the virtual image is magnified upright on the same side of the convex lens.

The larger the object distance, the larger the image distance, and the larger the virtual image.

In optics, the image formed by the convergence of actual light is called a real image, which can be undertaken by an optical screen; On the contrary, it is called a virtual limb resistance image, which can only be felt by the eyes. Experienced physics teachers, when talking about the difference between real and virtual images, often mention such a way to distinguish between real and virtual images: "Real images are inverted, while virtual images are upright."

The so-called "upright" and "upright" are, of course, relative to the original object. Therefore, the three virtual images formed by plane mirrors, convex mirrors and concave lenses are all upright; The real images made by concave mirrors and convex lenses, as well as the real images made by small hole imaging, are all inverted without exception. Of course, concave mirrors and convex lenses can also be virtual images, and the two virtual images they form are also upright.

Sorting out the problem-solving skills of various question types in junior high school physicsThe multiple-choice questions are not very difficult

Then students must control the time for answering multiple-choice questions when doing junior high school physics multiple-choice questions.

There are a total of 4 indefinite choice questions in junior high school physics, and you can only choose double when you are sure. Know how to give! Don't panic when you encounter a problem, you should solve it by finding hidden conditions, drawing, calculating column equations, eliminating methods, extreme value methods, etc. If you really can't answer it, leave it to the end to do it.

I recommend: Summary of junior high school physics answering skills.

For questions that require information by looking at a picture or reading a meter

First of all, we should carefully observe the junior high school physics charts, and try to get as much useful information as possible from the charts, some information may not be directly visible, you may wish to clarify the meaning of the topic first, and then look back at the charts, maybe there will be new discoveries.

Fill-in-the-blank questions tend to have some small calculations

This kind of junior high school physics question should pay attention to the conversion of units, so students must review the conversion of single Xun annihilation introduced in junior high school physics books before the exam. Even if the conditions give us standard units, it is possible that the horizontal line behind the answer is an uncommon unit. Mu Hall Chong must pay attention to this.

Problem solving ideas, punctuation

In addition to paying attention to the idea of solving the problem, we must also pay attention to the labeling of physical symbols. The physical quantities can not be marked repeatedly, and the principle of marking is to make the marking teacher understandable, usually using digital subscripts. In addition, there are not many steps in the calculation questions of the high school entrance examination, so it is best for students to write the calculation process in detail, write formulas for each step, pay attention to the use of units, and so on.

Methods for learning physics concepts in junior high school1. Taxonomy

Junior high school physics classifies the concepts learned, finds out their similarities and differences, and the concepts of junior high school physics can be divided into four subcategories The physical quantity of the concept is the product of several physical quantities, such as: work, heat; The concept is the ratio of several physical quantities, such as: velocity, density, pressure, power, efficiency; Conceptual properties of reactive substances, such as:

density, specific heat, combustion value, melting point, boiling point, resistivity, friction coefficient, etc.; There is no definition of concepts, they are just descriptive, such as force, boiling point, temperature.

2. Contrasting method

This method can be used to learn the two physical quantities that reflect the reversibility of junior high school physics, such as: melting and solidification, vaporization and liquefaction, sublimation and condensation, useful work and extra work.

3. Comparative law

For similar related concepts with the same words in the concept, the method of comparative learning can be used to find out the similarities and differences, and establish internal connections. For example, "gravity" and "pressure", "pressure and pressure", "work and power", "power and efficiency", "virtual image and real image", "magnification and enlargement", etc.

First easy and then difficult, and clarify the topic. After looking at the whole paper, you should answer the easier questions first, so as to concentrate on overcoming the difficult problems, so that you can make reasonable use of time and improve your test scores, so as not to consume most of your time due to one or two difficult questions, resulting in some shallow and easy test questions due to the haste of time and sloppy answers, resulting in mistakes, and sometimes even too late to answer.

The examination questions are detailed and detailed, "chewing the words", and repeatedly scrutinizing. Especially for questions that seem to be easier, it is more important to recognize the words accurately, see the sentences clearly, and strictly guard against illusions. Some topics seem familiar, and it is necessary to guard against negligence and omissions.

It must be done: first, do not miss the question; Second, don't read the wrong questions; Third, we must look at the topic; Fourth, it is necessary to look at the conditions and requirements of the whole topic.

Pay attention to some keywords in the question, such as the height and volume of the sound, how much the temperature rises and how much the temperature rises in the calorific calculation, and the lens imaging tells whether it is the object image distance or the objective lens distance or the image mirror distance;