Physical Chemistry Pre 90 for Junior 3, Physical Chemistry Pre for Junior 3

Chemistry: Memorized periodic table (first 18 hydrogen-argon).

In fact, there are too many things to carry in chemistry, such as hydrochloric acid rust, carbon monoxide reduction and iron oxide ......There are also 4 basic reflections, metal activity sequences, .........

Anyway, there are too many to memorize!!

Physics is much better, at the beginning of the main study of optics, acoustics (super simple, there are not a few questions in this year's high school entrance examination) optics: (convex lens) object near image is far large, object far image near small.

Acoustics: As long as there is sound, it is vibration.

Prevent noise: ears, objects, transmission routes.

Chemistry. Memorize all the chemical reaction definitions and formulas.

In the last chapter, acid, alkali salt, study hard, although the score of the high school entrance examination is not very large, but it is very important to lay a foundation for learning chemistry in the future.

It's enough to know the top 20 of the periodic table, and it doesn't matter if you can't memorize it, just remember where the commonly used ones are.

Physics. Mechanics accounts for more than the score, and every exam is the same, so focus on revision.

Optics. Electricity and Magnetism Clarify the definition in the book Just finish the exercises in the workbook.

There is nothing wrong with the first chapter of acoustics, just review it.

Simple, just look at it, define it, and write down the formula.

In fact, you don't have to be so much, you will encounter a lot of practice when you take classes in the future.

If you do more, you will be familiar with it.

Take a look at the book first, buy a teaching assistant, do some basic questions, don't forget to take a look at the knowledge window of physics, and read the additional content in the ** in the book.

The way is to memorize the definition, and then do more questions, I think it's similar to math, as long as you do more questions, it's almost the same, but the definition must be memorized.

Build a physical model in your own brain.

Physics and chemistry in the third year of junior high school is not difficult for physics and chemistry in high school, although I also studied very hard when I was sleepy in the third year of junior high school, but I finally did well in the physics and chemistry of the high school entrance examination. The following are the key points of learning physics and chemistry that I always shout early, you can refer to it:

1. Find the big rules; How each chapter of knowledge is connected and how it relates to each other. Flipping through the textbooks, our teacher strung together all the knowledge points in the textbook through the VCM imitation ruler and real experiment.

2. Write down what the teacher says, draw inferences, and be sure to turn it into your own things, and there are cliché things, preview, listen carefully, review after class, and summarize ......However, it really works.

As long as you keep persevering, you will get good results.

The main thing is to follow the teacher in class and try your best not to get distracted. The homework left by the teacher should be done as carefully as possible [this will detect your weak points] is not able to think of it.。。。 After class.

At noon or in the afternoon, I took the time to ask the teacher [chasing the teacher to ask]. Do more questions at home... You don't need a lot of rolls...

You don't have to do it all in one lesson. Pick some typical questions. and puzzles [only these questions can really improve you].

In terms of chemistry, the valency under the back. and equation steps, as well as reaction equations. That's OK

As for revision: Ask the subject teachers about the scope of this final exam... Put each lesson to review what to review and when to review.

It's all written on the desk calendar at home. On the table ... It's not too late to finish your homework every day.

Or try to complete the plan [sometimes, often encounter the plan can't catch up with the change] then please give yourself the time to your weak link...

I believe that, through your own tireless efforts ... It will get good results.

I'm also a junior high school student [the above is my study plan]. I think... Reviewing this stuff has to rely on personal characteristics...

Someone else's is not necessarily their own ...

First of all, you must have self-confidence, and you must be prepared to endure hardships, and you must memorize (like chemistry) and are too lazy to memorize, then go for it. The schedule should be regular, and the quality of the lectures during the day must be ensured. To grasp the basics, don't be afraid of trouble with the questions issued by the teacher, practice repeatedly, do more questions, and use questions to review knowledge points.

To make a question, you should associate the knowledge points that the questioner wants to investigate, so as to find the gaps, consolidate the memory, and then figure out all the problems of this kind. When the textbook is free, I flip through it to see if there are any missing knowledge points, don't rush to do it after taking a question, I have to think about what he wants to test me before I do it, I won't panic, and I will be more confident. Don't be discouraged if you don't know it, progress is also gradual, and if you have any questions, ask the teacher quickly.

Be diligent.

Hello. Along a staircase with an inclination angle of 30 degrees, the distance traveled along the staircase is 8 meters.

Think of the staircase as a right triangle.

8 meters is the length of the hypotenuse.

A 30-degree right-angled triangle with a right-angled side of 30 degrees is half the hypotenuse.

This is something you will learn in the third year of mathematics.

So the vertical upward distance is 4 meters.

The vertical distance, the horizontal distance, and the distance traveled along the stairs form a right triangle.

The distance to move along the stairs is 8 meters, and this distance is the hypotenuse of a right triangle.

The distance of vertical upward movement is the right-angled side of a right-angled triangle, and the corresponding angle of this side is 30 degrees.

The distance of vertical upward movement = 8 sin30° = 4m

Along a staircase with an inclination angle of 30 degrees, the distance traveled along the staircase is 8 meters.

Right Triangle: The hypotenuse is 8m, and the right angle of 30 degrees is the distance that passes in the vertical direction.

Opposite side hypotenuse = sin30°

Opposite edge = hypotenuse sin30° = hypotenuse 2

Because the condition for doing work is that the displacement in the direction of the force is subject to gravity and your supporting force, there are two types of work, one is gravity and the other is that you do the work equally.