I Don’t Want to Win Lying Down

Latest URL: This is a dream,

Xu Mang became the father of two children in his dream. The children were very smart. They had good academic performance since childhood and were very filial. They received scholarships every year and were soft-handed. As a result, when they were in high school, their youngest son Xu Yang fell in love and also found a tall man. When he returned from the airport, which was less than 1.5 meters tall, Xu Mang was so angry that he vomited blood.

Hello!

Professor Xie is calling you!

Wake up!

Suddenly hearing someone calling him, Xu Mang opened his confused eyes, and saw a girl in front of him staring at him, and fell into doubt for a moment, did he have any relationship with her? Keke is telling the truth...she looks average, she is not just a little bit worse than Xiaoman.

ah?

Who are you? Xu Mang looked at her curiously, his face full of doubts and incomprehensions about the situation in front of him, but soon he realized that something was wrong, the atmosphere of the whole classroom seemed to have fallen into silence, everyone around look at yourself.

What... what's going on here?

Why do you suddenly care about me so much? Could it be...the identity has been exposed? Glasses! Did you forget your glasses?

Xu Mang hurriedly touched his black-rimmed prescription glasses, but the glasses hung on his face, which was very strange. Although a pair of glasses can't change anything, it did change his temperament, temperament Change... People change with it.

This classmate!

Have you learned physics well? Professor Xie asked solemnly: Then solve the problem I mentioned just now. Two identical charged particles with mass m and charge e start to be separated from each other. Far away, one particle is at rest, and the other one is moving towards the stationary particle with velocity v and aiming distance p equal to 2ke^2/mv^2.

Then what is the center-of-mass neutralization angle? Professor Xie asked, Please answer.

ah?

Particle system dynamics?

I did not write this question.

Xu Mang recalled that when he wrote the dynamics of the particle system, he did not write any questions about the dynamics of the particle system.

It is estimated that this topic was written by him temporarily, but it is indeed a very good question. It involves the translational reference system of scattering particles and the kinematic equation formula under the action of the inverse square law.

certainly,

This is just one of the solutions. In fact, there are many solutions to this problem. Each solution is different, but the answers are almost the same.

oh...

I... Did I go to the blackboard to write the process? Xu Mang asked curiously.

right!

Come to the blackboard and write. Professor Xie said seriously: By the way...if you can't write this question, my basic physics course...you have to retake it. If your process and answers make me very uncomfortable Satisfied, I don’t need to come to my class in the future, I will give you a full score.”

hiss!

Fuck!

Is it such a big game?

Hearing Professor Xie's words, many people in the room gasped and said not to be scared, but it was more of a memory of Xu Mang. He did not hesitate to use his failure to verify a legend in the School of Physics. That is, don't talk back to Professor Xie, it's easy to get overwhelmed and walk around.

Xu Mang got up and walked through the crowd. Under the eyes of welcoming and sending off the heroes, he walked all the way to the blackboard, silently wrote down Professor Xie's question before, then stood in front of the blackboard, looked at the question in front of him, and for a while Some dazed.

like...

The blackboard is not enough!

Ahem!

Professor Xie?

What if the blackboards are not enough? Xu Mang asked cautiously, These four big blackboards are not enough for me to write... What if the writing is broken in the middle?

Professor Xie frowned, his eyes were full of doubts, and he said seriously: Impossible! This is a topic I proposed. Let alone four blackboards, two blackboards are enough. Anyway, you can write...write Tell me if you can’t stop, today’s class will not be held, it all depends on how you solve the problem.”

...

Oh! Xu Mang nodded, reluctantly picked up the chalk at hand, and wrote down the word 'jie' in a steady and skinny manner. Feeling a little twisted, he hurriedly added a colon, feeling more comfortable...

have to say,

I am used to writing papers, and then go back to solve such ordinary topics, I am not used to it.

original,

Everyone was not optimistic about Xu Mang, including this Professor Xie. However, when Xu Mang came up with a calculation process based on the translational reference frame of the scattering particles, Professor Xie realized that things were not as simple as he thought.

Immediately afterwards,

Professor Xie saw a very perfect calculation process of the kinematic equation formula under the action of a very perfect inverse square law force, and couldn't help showing a little surprise, but the surprised expression lasted for a short time, and soon returned to normal, scattering particles in the translational reference system , and the formula of the kinematic equation under the action of the inverse square law force cannot explain any problem.

The real difficulty lies in the back. It is necessary to draw a flat two-dimensional diagram and calculate the following process according to the two-dimensional diagram.

Swish Swish Swish,

Xu Mang continued to solve the problem, but at a slower pace.

etc!

When Professor Xie saw Xu Mang wrote a set of relationships, m1 and m2 were the masses of the scattered particles and the scattered particles m1=m2=m, his expression gradually changed from indifferent to a little panicked, as expected...he saw Xu Mang Imagine a particle group relationship.

Let the speeds of particles 1 and 2 relative to the center of mass translation reference system be v1c and v2c respectively, parallel and opposite, because m1=m2=m, v1c=v2c, vr=v1c-(-v2c)=v1c+v2c=2v1c.

this...

This student... is not easy!

Could it be that all the content has been learned in advance?

at the same time,

The students in the audience were a little shocked. They never expected that the contestant who was originally considered to be the bronze rank turned into the king rank, especially the two girls who were sitting in front of Xu Mang.

he...

so amazing!

Could this guy be pretending to be a pig and eating a tiger? The girl who woke up Xu Mang said to her best friend, Peking University...it's like Crouching Tiger, Hidden Dragon.

I just said it...the more he looks like he doesn't care, the more likely he is a peerless genius. The girlfriend said with a smile: Do you still question my words now? He must be a genius...just From that decadent energy, it's not a genius... God doesn't agree.

cut!

I refute!

Professor Xu from Fuda is not the kind of person you said. The girl said disdainfully: Professor Xu is a genius among geniuses, but at the same time he is very, very hardworking. I think... genius and hard work Always hooked up.

at this time,

Xu Mang's problem-solving process was still going on, but it was about to come to an end. However, in just ten minutes, Xu Mang had conquered everyone present, including Professor Xie who was standing by the side. He never imagined that there would be such a thing. A student exists.

Perfect!

so perfect!

It turned out to be exactly the same as my own answer, not even a single symbol was wrong.

Seeing that Xu Mang solved his problem smoothly, Professor Xie couldn't help but say, Okay! This colleague has done a very good job...

In the middle of the conversation,

Xu Mang came to the two movable blackboards next to him and continued to write the problem-solving process, but his strange behavior made many people a little confused. He had already solved the problem, so why was he still writing?

this...

What is this doing?

Professor Xie was about to open his mouth to speak, but the next second when the words came to his lips, he held back abruptly.

Center of mass translation reference frame?

This is...

The second solution?

Professor Xie was stunned for a moment. There is indeed a second solution, and it is very convenient, but it is not suitable for freshmen. He... how could he?

impossible!

at this time,

Professor Xie became more and more curious about this student. He stimulated himself again and again to refresh his understanding of freshmen. Is he really a freshman? Or did juniors, seniors, or graduate students come to make trouble?

three minutes,

All the students present witnessed the birth of a miracle. There seemed to be two completely different solutions to Professor Xie's problem, and the person who did it was the bronze contestant who had fallen asleep in class before.

I rely on...

Who is this guy? Why haven't I seen it? A certain student present asked with a puzzled face: Have you seen him? Wearing such earthy glasses... There is no trace of youth at all. , and...how do I feel twisted when I see his lazy look.

yes!

But their ability is higher than ours. The boy beside him sighed: There is a lot of pressure... If I have the same talent as Professor Xu, it would be great.

hehe!

You're thinking about farts! The boy mocked with disdain, and then continued to look at the blackboard. During the second problem-solving process, he found a problem after looking at it. The boy suddenly felt that the back of the student who answered the question seemed to be Where have I seen it.

This back...

So familiar!

...

Did I have hallucinations? The boy said cautiously: I... I think his back looks a bit like Professor Xu!

You're talking nonsense!

Before you thought that your girlfriend's back looked like a certain female star, and it was because of this relationship that you were with others. I saw...it looked like a fart! The boy next to him said angrily: Xu The professor is busy, how could he be so boring? He has a lot to do every day!

Too!

After a few more minutes,

Xu Mang had already completed the second problem-solving process, but the space left for him was only half of a blackboard.

what to do?

How should the third approach be presented?

for a while,

Xu Mang stood there stupidly, not knowing what to do.

At this time, Xu Mang was in high spirits, and finally felt a youthful feeling, but this feeling was too short, not even half an hour.

This classmate!

You are very good! Professor Xie showed a satisfied smile, and said to Xu Mang, You are far beyond my expectations. It is not easy to master these two methods at the same time... and it is not procrastinated. The whole process There is no trace of excess, not bad, not bad, not bad!

Xu Mang shrank his neck, and said cautiously: There is a third way of solving the problem...but I can't write it down.

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