Become a master from now on

Chapter 135 King Bi (ask for monthly ticket subscription)

Of course, because there is no object without force, Newton's first law is not a law obtained by experiment.

But what Fang Chao wants to use is not Newton's first law, but Newton's second law.

The so-called second law is expressed as follows: the magnitude of the acceleration of an object is directly proportional to the force, and inversely proportional to the mass of the object, and the direction of acceleration is the same as that of the force.

Various formulas derived from this come out.

The physics teacher didn't speak, and the students below were also deliberating and pondering carefully, trying to figure out the answer to this question. Some students had already started writing, and he had already figured out the first step.

"He doesn't seem to be able to do it. He hasn't touched the chalk yet."

"I guess he just said it casually...physics, that's how it is..."

But at the next moment, Fang Chao took two steps forward and began to write the answers in the upper left corner of the test questions on the blackboard that he could touch with his right hand.

Solution: Let the mass of the truck be M, the ratio of the resistance to the weight of the truck be u, the traction force of the truck before braking be F, the acceleration before and after braking of the truck be a1 and a2, and the acceleration of gravity be g.

Here, Fang Chao applied Newton's second law.

f-2uMg=0
F-uMg=Ma1
uMg=Ma
3uMg=Ma2
Assume that after the compartment falls off, the distance traveled by the truck within t=3s is s1, and the final speed is v1.

s1=v0t+1/2a1t
v1=v0+a1t
v1=2a2s2
Among them, s2 is the distance traveled by the truck after braking and decelerating.

Assuming that the sliding distance of the car after falling off is s, it is obtained that v0=2as
s=s1+s2-s
s=v0/3a+4/3v0t+2/3at2
s=36m
After Fang Chao finished answering, it took more than 2 minutes, but less than 3 minutes.

Excellent, perfect problem-solving steps and answers, Fang Chao is very satisfied with his answer this time.

The students below watched Fang Chao answer. Those students who started writing but paused for a while on certain steps had already been left far behind by Fang Chao. By the time they figured out the key points, Fang Chao had already Answer completed.

Everyone's eyes were on the blackboard at this time, because they were not stupid, and it seemed that this was really the case.

and……

Nima!
Why is the handwriting written by a high school student so beautiful? ! !

Not to mention such a heavy academic work, most students are faced with countless practice questions every day. Even students with relatively good handwriting in junior high school will be greatly reduced in high school, but the handwriting written by the male students in front of them , Although it is concise, it is pleasing to the eye, even the physics teacher can't help nodding.

Fang Chao's problem-solving ideas and answers are almost perfect, making people impeccable. Even the physics teacher can't find any faults.

But physics teacher Zheng looked at Fang Chao with a smile at the moment, and then said, "Since you are so good at physics, then I won't give you an answer question. I will give you a few questions and answers to see if you can answer them well." .”

"Yes."

Questions and answers are no better than answers to questions, and I am even a little nervous about answering questions.

Because physics questions and answers are different from mathematics to a certain extent, mathematics can be used to calculate the answer, while physics is more biased towards certain knowledge points, but most of these knowledge points are basic, Fang Chao does not care fear any challenge.

Even the students here are a little puzzled. Even the difficult questions have been solved. The so-called question and answer questions are nothing more than some basic points, such as mechanics, acoustics, optics, electromagnetism and so on.

Soon, Teacher Zheng looked at Fang Chao and asked, "One day in the cave is a thousand years in the world. Give me an explanation."

"Ok?"

Many students are at a loss, what is this?
However, Fang Chao didn't even think about it, and said directly, "According to Einstein's theory of relativity, when traveling in the universe close to the speed of light, the passage of time will be much slower than that on the earth. Living in this "hole" for a day, Years, decades, even millennia have passed on Earth."

"It's better to draw fire from the bottom of the pot than to stop the boiling water."

"Wow, teacher, your physics is taught by your Chinese teacher, right?"

Fang Chao was shocked, the physics teacher actually spoke out, pointing out the Chinese letter every now and then.

"Don't be skinny, answer."

"The necessary and sufficient condition for the boiling of a liquid is that the temperature reaches the boiling point and can continue to absorb heat. The raised soup dissipates heat to the air and the temperature drops, but the water returns to the pot and immediately boils again after absorbing heat. It does not cut off the heat source, but After withdrawing the fuel, it can fundamentally stop the liquid from boiling."

Fang Chao replied almost without thinking.

"In what year was Newton discovered the force of gravity?"

"Fuck!!"

Holy shit! !
Too cruel! ! !

Even if Fang Chao has a system like a BUG that makes his memory amazing, it doesn’t mean that his memory is so good that he can remember everything, just like the year and month of Jay Chou’s first album. Die-hard fans or even fans who have listened to Jay Chou's music for decades may not be able to clearly know, and this is only in the past few decades, but Newton's period can be traced back hundreds of years ago. Isn't it good on one level?I can't even remember the release date of Jay Chou's first album, let alone the time when Newton discovered gravity.

The physics teacher asked this question too hard...

Who would have thought that he would be so unexpected.

You say it is not a physics problem, right?Isn't it a physics question?Newton wasn't a physicist?Gravity has nothing to do with physics?Everything is obviously related to physics, so it is a question related to physics...

Finally, Fang Chao shook his head and said, "I'm sorry, teacher, I can't do this question."

Only then did the physics teacher show a slight smile, thinking that you really know everything. You are so awesome, so there are things you don't know.

And many students are holding back their laughter at the moment, can't you, kid, be able to pretend?You don't have to be obedient now, you are still too young in front of the physics teacher.

"Are you a senior in high school?"

Physics teacher Zheng asked, it is impossible for the first year of high school to involve these knowledge points, and for the second year of high school, he knows all the students in this year, except for poor students, but he can perfectly answer the physics question on the blackboard. How could the student who asked the question be a poor student, so he immediately ruled out the first and second grades of high school, and directly raised the other party to the level of senior three.

Among today's students, many students are mature, and some students look young, but they are really in their third year of high school. This is hard to imagine.

"Teacher, I am not."

Fang Chao shook his head.

At this time, one of the students suddenly found something in the corridor. He picked it up and looked at it.

"Grass!"

"It's that bullying king!!"

(End of this chapter)