How to do physics questions efficiently in the fourth year of junior high school?

You still have to rely on yourself to do this thing, first of all, avoid doing the same type of questions too much, it is a waste of time, the key is to master the physical model of this type of question, as long as you know the model, no matter how you can change it; The other is the set of mistakes; You must do it, but not blindly copy down your mistakes, but think carefully about why you are wrong, the thinking loopholes are in the **, and what is the trick to making this question. The last is to learn to associate, I should emphasize this when I tell others about my learning methods, association is extremely important, when doing a problem, we should associate the physical ideas, mathematical ideas, related facts and corresponding equations of the problem. Association is also an extremely important way of memorizing.

In junior high school, the amount of physics thinking is not large, and the emphasis is on reviewing problems, selecting formulas and calculations. First of all, you must be proficient in publicity and concepts. And when doing the questions, you should ensure that you are fully engaged, carefully review the questions, and calculate carefully.

If you encounter difficulties in the exam, you can let go of them appropriately first, so as to leave enough time for the final questions. Don't stick to a question and be stunned, you can't be blinded. That's it!

Let's read the book first, and I feel that if I understand the book, the question will be done.

When doing physics problems in junior high school, its skills are mainly to judge the principle of the test questions, and only after we know the principles can we conduct effective analysis and find the solution to the problem.

Junior high school physics is more conceptual, and there are fewer calculation problems, so you can master all the concepts in the book.

The skills that can be done should be better if you do more questions.

When S is closed, S1 is disconnected and late, and when P is at the B end, the pin Li bulb is connected in series with R2, and U total = R light =

When S1 is closed, when P is at the A terminal, R1 and the bulb are connected in parallel, and the current through R1 is R1=12

In a hurry? If you're not in a hurry, you'll give it to you tomorrow!

Column Equations: Equations.

1. Similar, so oa oc = oc ob --- oc 2 = oa * ob.

Equation. 2. Parabolic equations.

Equation 3, ACB is a right angle, the relationship between the three angles of the triangle can be obtained, and then the relationship between the sides can be obtained by the cosine theorem.

The result can be solved. You have to do the math yourself, which is more time-consuming.

After reading it for a long time, I don't know why it's a physics problem.

To study and review effectively, you must not only learn to follow the teacher, but also learn to make a plan that suits you according to your actual situation.

1. Generally speaking, the knowledge taught by the teacher is carried out according to the syllabus and examination syllabus, so it is very important to concentrate in class. However, the knowledge taught by the teacher is for all students, and each person's specific grasp is different, so you must learn to adjust and make a plan that suits you according to your own situation. The main purpose of the program is to improve the effectiveness of learning, and at the same time, it is also conducive to the formation of a good study habit.

If you have poor writing skills, write an essay a week, practice reading comprehension a day if you are poor at reading, and take some time out every day to memorize and recite if you are poor in basic knowledge, etc.

2. Learn to master the ability of speed reading memory. Speed reading and memorization is an efficient learning and review method, and its training principle is to activate the potential of "brain and eye" and cultivate the formation of eye-brain direct reflection reading and learning mode. The practice of speed reading memory refers to the "Elite Special Brain Speed Reading Memory", with software practice, more than an hour a day, a month's time, you can increase the reading speed by 5-10 times, memory, comprehension, etc. will also be improved accordingly, and finally improve the efficiency of learning and review, and achieve good results.

At present, many classes in our school have carried out the "Vacation Speed Reading and Shorthand Training Class" to help students improve their learning efficiency, using the "Elite Special Whole Brain Fast Reading and Memory Software", which can be used for reference.

3. Doing practice is indispensable, but don't blindly use the tactics of the sea of questions and make a mess of yourself. When doing the questions, resolutely complete them independently, eliminate plagiarism, and eliminate the tactics of the sea of questions. You will never be able to finish the test questions, but the question types are limited, so you must learn to reflect, categorize, and sort out the corresponding solution ideas.

In the process of studying, we should also learn to summarize in stages, understand our recent learning situation, and adjust and improve.

7、a8 、d

9. The specific heat capacity of water is larger than that of sand and gravel, absorbing the same heat, the water temperature rises less, and the mechanical energy decreases! Because the quality of the water has become smaller!

Observing the flashlight, the students first unscrewed the back cover to observe: how is the battery placed? Before the positive electrode and after the negative electrode.

How is the back cover connected to the battery? The negative pole of the battery is connected to the back cover.

What is the function of the spring on the back cover? 1. Wire; 2. Squeeze the battery so that the positive and negative electrodes of the battery are in good contact;

Try to push the metal slider forward, the metal slider is connected to the light bulb? The metal slider is connected to the metal housing, and when the metal slider is connected to the positive press sheet, the bulb emits light.

When the metal slider is pushed forward partially, press the button, and the slider is also connected to the positive terminal of the battery, and the bulb glows. Unscrew the front to see how the bulb is connected? The tin block at the tail of the bulb is connected to the positive electrode of the battery, and the other metal parts are connected to the metal housing (negative electrode).

Why is there a piece at the tail of the bulb? What does it do? The role of the tin block is to act as a wire, connecting the positive pole of the battery and the filament.

The battery is, of course, mounted in this way from positive to negative. Springs are also part of the circuit that act as both conductors and are designed to prevent loosening. Slide the metal slider and the light will have a noticeable change in brightness and darkness.

Both the bulb and the metal slider are connected in series. The role of the tin block, this is not very clear, it seems that there is not.

The battery is connected in series, the back cover and the battery are also connected in series, the spring is to make the battery close contact, and the bulb does not emit light. The tin block at the tail of the bulb is electrically conductive.

It should be the connector of the wire, how can the filament be bright if it is not connected.