High School Math Physics Questions! Mentally prepare for the first year of high school!

Personally, I think that math and physics in high school are super simple.

As long as you listen well, there is no problem in learning well.

Also, remind me, you little kid is going to read the college exam papers now, with your junior high school level, of course, you are confused, otherwise, three years of high school will eat. By the way, whether you can learn well in high school is not necessarily related to the quality of your junior high school grades, because those things in junior high school are just small tools, as long as you can use them. In fact, the middle level of junior high school students and top students reach the starting line of high school exactly the same, because the requirements for junior high school knowledge are only at the middle level.

Therefore, if you are very good now, I advise you not to be complacent, thinking that you have an advantage in high school, which is very wrong; If you have average grades, then don't be discouraged and think that your starting line for high school is lower than that of the top students, which is also wrong, in fact, your starting line is about the same. If you knew that, I think you'd be able to learn it pretty well.

As for how to learn well, the answer is the same, of course, you have to work hard.

And a lot of backrests in junior high school. How much time you spend is not the key, the key is efficiency, what you learn, whether you can digest it in time, understand and master it. It's a bit difficult, because you have to use your brain to think more, as long as you are not afraid to use your brain, you can learn well when you encounter problems.

The high school exam paper has a maximum score of 150. Generally, people with normal intelligence, as long as they study carefully and use the correct method, they can take the test of about 100-120. But if you want to take the test, it's hard to have no talent, hehe...

Mind you, high school is a new beginning. In fact, most of the subjects are decoupled from junior high school. There is a big gap between them, which means that what you do in middle school doesn't have a big impact on high school (it just affects what kind of school you go to in high school).

I'm lazy, I usually only listen in class, and I never do much questions, and I can score between 96 and 108 in mathematics with a score of 150. Physics is not good, usually do the questions are okay, but it is difficult to pass the exam, you must study carefully. In fact, the first year of high school is quite simple.

However, most of the test centers are in the first year of high school, so you can't be lazy this year.

Hehe. I love high school physics.

And junior high school physics is far from yours.

As a result, the physics choice for the college entrance examination was correct, and all the big questions were answered.

Suggestion; I followed the teacher in my freshman and sophomore years of high school.

For each chapter, the teacher will do the exercises after speaking; When doing exercises, mark those that you don't know and wait for the teacher to talk about them. After the teacher explains, write your own consciousness next to the question;

It's important to think a lot, but don't think too complicated (it's better to be able to understand the new knowledge with old knowledge) It's also important to be humble, sometimes the teacher's opinion is not as good as your own, but you also have to think about why the teacher says this (most of the time because it's a conventional solution, it's the foundation).

If you have any questions, please feel free to send me a message, I can help you understand some knowledge.

I'm going to high school this year too.

If you're interested, add me.

(1) Qualitative analysis: the iron exerts a force, the iron has a tendency to move on the board, the board has a sliding friction force on the iron, and the iron has a sliding friction force on the board, and this force is in the same direction as the applied force, so there is a tendency to move on the board.

2) The wooden board has a sliding friction force against the iron block, the magnitude is 2mg=4n, and the ground has friction against the wooden board, and the maximum static friction is about equal to the sliding friction force 1(mg+mg)=2n, so when a force is greater than 2n (less than 4n) is applied to the iron block, the wooden board will move, and the wood block and the iron block move together.

Addendum: The force you mentioned applying to an iron block must be greater than 2n for the wood block to have an acceleration.

The iron block moves on the wooden board, and the wooden board has a sliding friction against the iron block, and at the same time, the iron block also has a sliding friction against the wooden board, the magnitude is 2mg=4n, and the ground also has friction on the wooden board, and the maximum static friction is about equal to the sliding friction force 1mg=1n, and the maximum static friction is less than the friction of the iron block against the wooden board, so the wooden board will move.

There is friction between the iron and the plank, and the force that makes the plank move is the friction between the iron and the plank.

What about the figure? And you'd better get the question out there.

Because the iron has friction against the plank, according to Newton's third law (interaction force), the wood also has friction against the iron and in the opposite direction.

When the speed is reduced to half of the original speed, the time taken is half of the time to stop, and the time to stop is 40s.

The displacement of the first 20s of ii is 30m, and the average velocity is , then (v0+v0 2) 2=,v0=2m s

iii. The average velocity of the second stage is half of the final velocity of the first stage, i.e., the displacement of this section is 10m, and the total displacement is 40m

When the car enters the station, turn off the engine to do uniform deceleration linear motion, when sliding x1=30m, the speed is exactly half of the initial velocity, v0 2) 2-v0 2=2ax1

Then it taxied again t2=20s before stopping.

0=v0/2-at2

x2=(1/2)(v0/2+0)t2

The total displacement is x=x1+x2=

The speed when the engine is turned off v0=

The total time for the car to coast t=t1+t2=

When a person rides a bicycle to the east at a constant speed, he feels that the minutes are blowing from the south, indicating that the wind is following the speed in the east direction.

When a person is driving at a constant speed of 4 3 m s to the north, he feels that the wind is blowing from the west, indicating that the wind is in the north direction.

The combined velocity of these two velocities is the magnitude of the wind speed: v = 4 2 + 4 3) 2] = 8 m s

Wind direction tana =4 3 4 = 3

a = 60 degrees.

Wind direction: 60 degrees north-east.

108km h=30m s 1 question: a=(0-30) 5=-6m s2 2 2 question: s=30* I don't know if it's right. I haven't used it for a long time and forgot.

108km／h=30m/s

Let the acceleration be a, then a t=30, t=5, a? Do the math yourself.

x52=？Do the math yourself.

Sliding friction f= gcos45°=50 (n) The component of gravity along the inclined plane f=GSIN45°=50 2 (n) So, the minimum value of thrust = f-f=50(1-2) (n) The maximum value of ulnar friend of thrust = f+f=50(1+ 2) (n) The reason for this problem is that the direction of friction is unknown Hope it helps you!