"Liu Yichen, the evening self-study is about to end, why don't you pack up and get ready to go home!"

Just when Liu Yichen was immersed in the joy of answering questions in the physics textbook, he was pulled out by Deng Linghao's voice.

"I live on campus, not at home!" Liu Yichen said angrily: "Only cowards can go to school. Real warriors are all students who live on campus!"

Deng Linghao's home is not far from Liu Yichen's home. Unlike Liu Yichen who was arranged to live on campus, Deng Linghao is a day student and does not live on campus. He goes home to eat at noon and returns to school before class. After the evening self-study, he also rides his bicycle home.

Or his parents take him home.

"Nonsense, my mother said that only day students can eat well, sleep well, and keep up with nutrition." Deng Linghao said unconvinced.

Liu Yichen rolled his eyes.

Do you still take it seriously?

What a little brat!

At this time, the bell for the end of evening self-study rang. Some day students left the classroom with their schoolbags on their backs, and some dormitory students also returned to their dormitories.

Liu Yichen did not. He continued to stay in the classroom, because the lights in the classroom would not be turned off until 11 o'clock in the evening, and the dormitory would not close until 11:10. Naturally, he had to make good use of this time.

When I return to the dormitory, my roommates will take a shower and chat, but it is not as quiet as studying in the classroom.

Ignoring Deng Linghao's angry departure, Liu Yichen continued to finish the remaining three after-class exercises.

The remaining three questions are either to know various forces and require the final acceleration; or the object is moving at a certain speed and brakes in an emergency. How many meters does it move after braking, and then to find the relationship between the road surface and the tires?

The kinetic friction factor between them. Either there are five buckets inside a truck, and one bucket is placed on top of two buckets, that is, the three buckets a, b, and c form a triangle. The three buckets are not fixed by ropes and remain stationary together with the car.

, and then judge the increase or decrease of the support force for barrel c under the given conditions and find the critical acceleration of barrel c moving away from a to the right of b.

These three questions are all comprehensive type questions, and they all involve the synthesis and decomposition of force, as well as the overall combination of force and motion.

Liu Yichen drew a force diagram under each question, and then synthesized and decomposed the force. The decomposition direction was basically along the direction of motion, and then solved it based on the final resultant force or Newton's second law and Newton's third law.

Acceleration can either be solved to find the velocity, or the force required by the conditions.

"It's not difficult. When I was in college, why didn't I give up college and go to high school again? Otherwise, it should be no problem to get into a 985 college." Liu Yichen muttered to himself.

Whether it was the previous high school mathematics compulsory course 1 or the current high school physics compulsory course 1, he felt that it was easy to understand and the answers he gave were all correct, indicating that he basically mastered them.

Could it be that after time travel and rebirth, my IQ has become higher? Or have I become smarter!?

Looking at the time, it was still early before lights out. Liu Yichen picked up High School Chemistry Compulsory Course 1. After reading the preface and table of contents, he turned directly to the appendices at the back. It had been too long and he had forgotten a lot of chemistry knowledge.

But he still remembered, don’t rush to read the main text first. After reading the table of contents, go to the appendix. Liu Yichen looked at the appendix. Appendix 1 is about measures to deal with laboratory emergencies and common waste disposal methods. This is some common sense.

As well as the experimental operation questions in the chemistry test paper, which are often tested. After silently memorizing it, he turned to Appendix 2, which is about some chemical safety labels. It is not a common test question, but it is common sense and will be tested occasionally.

Of course, Liu Yichen will focus on Appendix 3, Appendix 4, and Appendix 5. Appendix 3 is about some common chemical terms, such as Avogadro's constant, hypochlorous acid, sodium hypochlorite, etc., some of which are available in junior high school.

But most of them are only exposed to high school. Appendix 4 is about the solubility table of some acids, bases and salts. Here you can see cations, anions, which substances are soluble, easily soluble, volatile, and which ones

It is slightly soluble and insoluble. As he memorized this list, many memories hidden deep in his mind continued to emerge, making it easier for him to learn.

When he turned to Appendix 5, regarding the periodic table of elements and the relative atomic mass table, junior high school students only need to write down the first 20 and they are almost always successful, while high school chemistry requires memorizing the entire table, including isotopes, and the atomic masses are located in

Which clan.

"After graduating from high school, apart from a few majors, chemistry is probably the most useless!" Liu Yichen laughed to himself after spending a lot of effort and finally memorizing the entire list.

Once upon a time, chemistry was also his strong point. He could easily get 90 points out of 100, and even get 100 points accidentally.

It's a pity that when they go to college and study civil engineering, they don't need to learn chemistry anymore. What the school teaches them is to be a brick-moving person with peace of mind. They don't need to think too much about anything else.

Their destination!

After getting up and moving his body a little, Liu Yichen turned to the main text, which is Chapter 1, Matter and its Changes. In this chapter, the classification and transformation of matter, ionic reactions, and redox reactions are introduced. This part of the content follows Liu Yichen.

After reading the appendix and reappearing some memories, it was not difficult to learn. He read the book like flipping through a book and quickly finished the first chapter.

Chapter 2 is about the important elements sodium and chlorine in seawater. Here we introduce sodium and its compounds, chlorine and its compounds, the amount of substances, and the mole.

When Liu Yichen finished reading the second chapter, it was already 11 o'clock, and the classroom lights were turned off on time, leaving only the dim yellow light outside.

Holding the chemistry textbook in his hand, Liu Yichen left the classroom and closed the classroom door. The last student to leave the classroom had to close the door. As for the location of the classroom door key, every student knew it.

Liu Yichen opened his legs and walked towards the dormitory building.

"Fuck~~ It's over. The calculation was wrong. My special situation at this time was not taken into account. My movement speed is slower. The same displacement will take more time!" Liu Yichen watched the door of the dormitory building close.

I was stunned and suddenly thought I had made a mistake!

According to kinematics s=v0t1/2*at2, when using uniform speed, the acceleration is 0 and s=vt. When v is relatively small, s remains unchanged and t will be relatively large.

what to do?

Sleeping on the streets?

"Uncle, aunt, I'm late, can you open the door and let me in?" Liu Yichen shamelessly begged the uncle and aunt in charge of the dormitory.

"What's going on with you classmate? Didn't I tell you that the lights in the dormitory building are turned off at 11 o'clock and the doors close at 11:10? Why are you still late?" the dormitory manager said angrily.

"Old Wang, didn't you see that this child is holding a textbook in his hand? He must be reading too hard and not paying attention. This child is very good-looking, he must be a good boy!" Another aunt didn't want to speak out.

After scolding Liu Yichen, he suddenly became friendly and even said angrily to the dormitory supervisor.

The dormitory aunt opened the door and said in a gentle voice: "It's important to study, and you should also pay attention to rest. It's not worth it if you don't get sick!"

When Liu Yichen heard the words of the dormitory aunt, he felt warm in his heart. The dormitory aunt was considerate, unlike the dormitory uncle, who was so fierce. No wonder he was named Wang instead of Qin. He was probably sixty years old and still had such a bad temper.

!

"Young man, do you have a partner? Let me tell you, my little daughter is in the third grade of junior high school this year. She is in Qingcheng No. 2 Middle School and will go to high school next year. Let me introduce you to her..." The dormitory aunt is very talkative.

But Liu Yichen's expression changed and he quickly started!

Thought he was a good person!

It turns out that he is lusting after my body!
Chapter completed!