The past is like wind, and infatuation is just difficult to understand;

Let's send each other off with wine, but we can't see each other off with a misty figure!

I drank a bottle of Nongfu Spring.

Nongfu Spring is a bit sweet!

Why do I feel a little bitter?

Liu Yichen even had a bad taste in his dinner. The past is easy to say, easier said than done. After all, he owed a love debt in his previous life, and he cannot live without it in this life.

After munching on a big chicken drumstick, Liu Yichen went back to the dormitory to take a shower. Their dormitory was on the sixth floor, which was the top floor of the dormitory building. He had just finished running and was covered in sweat. Liu Yichen felt uncomfortable without taking a shower, and he couldn't even think about studying at night.

.

It's just that there is no elevator in this dormitory building. The soreness when climbing the stairs made Liu Yichen grimace. The abominable academic system. If it weren't for the abominable system tasks, he would have to endure this pain even if he climbed the stairs.

After finally returning to the dormitory, the dormitory was empty. His three roommates were not in the dormitory, and he didn't know what was going on. The classmates in their class all lived together in the same class, with eight people in one dormitory, but he was...

Living in the most remote room, this room is relatively small and only accommodates four people. The other three are all seniors in high school, and he is the only rookie in the first year of high school!

Liu Yichen took out the package that Mr. Deng packed for him, took out his underwear and a change of clothes from it, and went into the bathroom to take a shower. The environment in the dormitory building was very simple, and the facilities were relatively old. Even the shower head was probably seven or eight years old.

, it’s really incomparable to home.

After taking a comfortable bath, Liu Yichen soaked his change of clothes in water and then washed them with soap. At this moment, he missed home and Mr. Deng at home!

At home, Mr. Deng arranges everything properly. Mr. Deng washes the clothes and mops the floors. However, at school, you have to clean the bathroom by yourself every day, and there is general cleaning every week.

Those who do not pass the evaluation will be notified and criticized.

His home is not far from Qingcheng No. 1 Middle School. He lives in Guilin and it takes about 15 minutes to walk there. He most hopes to eat and live at home, but he was suppressed by Mr. Deng and Mr. Liu. According to Mr. Deng and Mr. Liu,

He has grown up and needs to learn to be independent, otherwise he will starve to death outside when he goes to college, so he is cruelly arranged to live on campus and is only allowed to go home once a week on weekends.

With a mature soul, Liu Yichen will naturally no longer complain. Instead, he thinks this is a good thing. He can study in school with peace of mind and move towards academic supremacy with peace of mind, instead of living under the tyranny of Mr. Deng and Mr. Liu at home.

After drying the washed clothes, Liu Yichen walked out of the dormitory and saw the campus lights blooming. On the basketball court on the playground, students were still playing basketball enthusiastically. With Yao Riyue logging into the NBA and succeeding, basketball became completely popular.

, has become the number one sport among students. I don’t know how many people have begun to like basketball, and girls also like boys who can play basketball. Even if a boy has poor academic performance, as long as he is good at basketball, he can easily make friends.

Meet beautiful girls as friends.

As for the teaching building, the lights are brightly lit, every classroom is on, and the sound of reading can still be heard. It is obvious that in such an environment, more students are focused on learning and study consciously instead of waiting until

At the beginning of self-study in the evening, I stayed in class honestly and fought wits with the patrolling teacher.

Liu Yichen walked with some heavy steps, and felt a little pain in his balls every time he went down the stairs. He had done little exercise since junior high school, only shooting, and his physical fitness was naturally deteriorating. Now he is said to be powerless.

The scholar is not an exaggeration.

Today's five-kilometer jog would have killed him.

But at least I have made a breakthrough. If I keep running tomorrow, I will feel relaxed after a few days.

There is always a film between easy and difficult. As long as this film is broken, nothing will be difficult or difficult.

Arriving at the classroom with some pain, I sat down silently in my seat. Although I hadn’t started my evening self-study yet, I was already halfway through the classroom. I had just started high school, and I was still in a familiar environment, so I chatted more.

Liu Yichen picked up the physics textbook, which is the compulsory course for high school physics 1 published by the People's Education Press. In this version of the textbook, the preface is - Physics: the science of matter and its laws of motion. From sunrise to sunset, Chensu Lie Zhang and other nature

Various magical phenomena introduced physical phenomena and introduced the historical development of physics. Aristotle, Archimedes and other early scientists developed the lever principle, the law of buoyancy and other laws. In the 16th and 17th centuries, Galileo Galilei

Together with Newton and others, he created a systematic theory of mechanics. The establishment of the classical mechanics system marked the official birth of physics in the modern sense.

The entire high school physics is mainly about mechanics, magnetism and electricity. Matter and its laws of motion are ultimately mechanics.

As for more advanced quantum mechanics, relativity, etc., many of them are brushed aside in Chunqiu's writing style, because even physics teachers have a vague understanding of such advanced physical theories, and they can't even scratch the surface, let alone teach students.

Mathematics, physics, and chemistry are Liu Yichen's strengths. He has already made up his mind to choose science subjects when he is divided into arts and science classes at the end of this semester, because what he fears most is the course of politics. He can't learn it no matter how hard he scores, and he can barely score 60 points.

Failing is normal.

After reading the preface, I turned to the table of contents. This high school physics compulsory course 1 only has four chapters, which are the description of motion, the study of uniformly variable linear motion, interaction forces, and the relationship between motion and force. This is much deeper than junior high school physics.

, especially the in-depth and switching of the reference system, is the difference between high school physics and junior high school physics at the beginning. The difference in displacement and distance, as well as the introduction of acceleration, all increase the depth of physics from the beginning.

In the second chapter, the study of uniform linear motion is mainly about the calculation of acceleration, displacement, and time. The focus is to analyze the physical concepts represented by each symbol and the calculation of the formulas based on the diagram. The focus of the third chapter is Newton's third law.

, thus unfolding the decomposition and synthesis of force, and calculating forces in other directions according to the given conditions. Chapter 4, the relationship between motion and force, truly cuts a watershed with junior high school physics, Newton's first law,

Newton's second law, combined with Newton's third law, basically established classical mechanics, perfectly combining force and motion.

The reason why Newton is known as a god-level figure in physics, the biggest among the big guys, is because he established the classical mechanics system. This classical mechanics system has deeply influenced the entire world since Newton was established until now. Although at the microscopic level,

It has been impacted by quantum mechanics, the theory of relativity in the universe, etc., but it is undeniable that it is a classic!

For example, Newton's first law: All objects always remain at rest or move in a straight line at a uniform speed unless acted upon by external forces!

This law is also called the law of inertia. It is tested on almost every test paper, and the test is not one-point or two-point.

There is also Newton's second law: the acceleration of an object is directly proportional to the force on the object, inversely proportional to the mass of the object, and the direction of the acceleration is the same as the direction of the net external force.

Expressing this law using a formula, it is: f combined = ma!

In addition, as stated in Newton's third law, when two objects interact, the forces exerted on each other are equal in magnitude and opposite in direction.

This constitutes almost all the questions on force and motion in high school physics. Just a few Newton's laws made countless candidates cry in the exam, and caused countless students to choose liberal arts when they were divided into liberal arts classes. They just didn't want to suffer.

The torture of mathematics and physics.

Liu Yichen was immersed in textbooks. During the evening self-study on the first day of high school, only the head teacher would patrol the class, and other teachers would not show up until the next day. The first week of classes was more about getting to know the teacher, and the teacher guided the students to

The combination of junior high school and high school knowledge is a transitional time. It will not be until the second week that students will gradually enter the field of high school knowledge.

"This classmate Liu Yichen is ranked last in the high school entrance examination class, but he has a good attitude towards learning, he is handsome, and he studies seriously. He is a good learner. You can pay close attention to him." When Teacher Lin was patrolling the class, he saw other students.

The students and children were confused and did not pick up the textbooks to prepare for tomorrow's homework. However, Liu Yichen was immersed in reading, drawing and writing on scratch paper or notebooks. He looked very serious at first glance, and his affection for him increased sharply.

When passing by Liu Yichen's table, he saw Liu Yichen reading a physics textbook with various ghost symbols on it. Teacher Lin had a headache at first sight. She is a Chinese teacher and teaches Chinese. When she saw these mathematical symbols and physical symbols, she

I feel a headache.

Liu Yichen didn't know this. At this time, he was highly focused and was learning the application of Newton's laws of motion. He combined it with after-class exercises to continuously deepen his understanding and memory.

The exercise is about skiing. A skier, the total mass of the person and the equipment is 75kg, slides down the slope in a straight line with an initial speed of 2m/s and a uniform acceleration. The slope angle of the slope is 30°. The distance he slides down in 5 seconds is

60m. Find the pressure the skier exerts on the snow surface and the resistance the skier experiences.

Liu Yichen drew a straight line next to this question, making a 30° line and angle, and then drew a normal line along this line to start the decomposition and synthesis of forces. For example, this skier, as a particle, was subjected to vertical

The straight downward gravity, the supporting force of the snow surface perpendicular to the snow surface, and the downward friction force perpendicular to the snow surface.

It is sliding down a straight line with uniform acceleration, which means that the vertical force of the line decomposed into 30° by gravity is as large as the supporting force of the snow surface. The force in the direction of movement after decomposition of gravity minus the friction force is equal to the resultant force, and the resultant force provides acceleration.

Bring the known conditions into s=v0t1/2*(at2) to find the acceleration a=4m/s2.

According to Newton's second law, fn-mgcosθ=0 in the y direction; mgsinθ-f mol=ma in the x direction. Bringing in the known conditions, we get f mol=75n and fn=650n.

According to the force diagram, the direction of each force is determined.
Chapter completed!