Xueba, I beg you to go and escort him quickly!

"I love it! Xu Heng praises it!"

"..."

A sudden burst of bragging and admiration.

With black lines on his face, Xu Heng quickly quit Q and disappeared.

Then I clicked on WeChat and found Fang Zhonggui, "Professor Fang, do you have any good physics problems? Give me some difficult ones! To pass the time..."

first sentence!

Fang Zhonggui almost vomited blood!

What is difficult?

How much for you?

Do you think I'm Doraemon's treasure bag? !

Fang Zhonggui clutched his forehead and felt a headache.

You can answer such questions for me in 15 minutes. Where do you ask me to find problems for you?

Xu Heng, "Professor Fang?"

Suddenly Fang Zhonggui felt something was wrong.

Whispered, "This kid won't regard me as a tool for making questions and finding questions!"

The veins on Fang Zhonggui's forehead throbbed violently, "This kid!!!"

But what can we do?

I am a professor!

If there is no question, wouldn't this professor be in vain?

In addition...

Fang Zhonggui also wanted to know where Xu Heng was going.

Finding a mock test paper in the drawer, Fang Zhonggui sent it to Xu Heng question by question.

topic:

己知一质点的运动方程为r=(5sin2πt)i(4cos2πt)j(单位为米)，则该质点在0.25s末的位置是多少？，从0.25s末到1s末的位移是多少？

Xu Heng, "They are: 5im, (-5i+4j)m."

Soon, without even a minute, Xu Heng gave the answer directly.

Fang Zhonggui's heart trembled.

Sure enough, it was very fast!

Not only fast, but also very accurate.

Come again!

topic:

A very thin mica sheet (n=1.58) is used to cover one slit in the double-slit experiment. At this time, the zero-order bright fringe on the screen moves to the position of the original seventh-order bright fringe. If the incident light wavelength is λ =550nm.What is the thickness of this mica sheet?

It was less than 1 minute again.

Xu Heng, "6.6*10 (-6 power) m."

Fang Zhonggui, "!!!"

Come again!

topic:

After an electron is accelerated by an electrostatic field, its kinetic energy is 0.25 Mev. Calculate: (1) the mass of the moving electron; (2) the moving speed of the electron; (3) the wavelength of the de Broglie matter wave of the electron.

This time, it was still less than 1 minute.

Xu Heng, "Professor, do you need a process? No, I will give you the answer directly..."

Fang Zhonggui's scalp was numb.

If the result is correct, is the process still important?

This is not an exam!

Xu Heng, "Or... even the professor thinks it's very easy... I think it's better to forget it! Professor, please find some difficult questions for me!"

"Pfft..."

Fang Zhonggui no longer dared to look directly at Xu Heng.

"Okay! You kid! Since you think it's easy, I'll give you a difficult one!"

Fang Zhonggui took out his notebook.

This is what he prepared for the postgraduate entrance examination for the Department of Physics.

I can't hide now!

Fang Zhonggui, "Student Xu Heng, pay attention to the questions."

Xu Heng returned Fang Zhonggui with a smiley expression, "I knew the professor was helping me warm up just now."

Fang Zhonggui, "%￥%##￥%..."

topic:

As shown in the figure, two rigid light rods AB and BC are firmly glued together at end B, the angle α between the extension line of AB and BC is an acute angle, the length of rod BC is l, and the length of rod AB is lcosα. The three points B and C are fixedly connected with a small ball of mass m to form a rigid system.

The entire system is placed on a smooth horizontal table top with smooth vertical baffles fixed on it.The rod AB extension line is perpendicular to the baffle.

Now let the system move toward the baffle at a speed of V0 and direction AB.

At a certain moment, the ball C collides with the baffle, and when the collision ends, the component velocity of the ball C in the direction perpendicular to the baffle is zero, and the ball C does not adhere to the baffle.

If after ball C collides, ball B collides with the baffle before ball A, find the conditions that the included angle α should satisfy.

This time Xu Heng didn't reply to him every minute.

Fang Zhonggui finally felt at ease!

He leaned back in his chair, feeling a little complacent.

Because in his opinion, he tested Xu Heng's bottom!

It is also at the level of the postgraduate entrance examination.

In terms of physics, Xu Heng's strength lies here.

"call……"

Fang Zhonggui looked at the questions he had posed, and he was a little relieved that he could stump Xu Heng.

5 minutes passed quickly.

Fang Zhonggui, "It seems that he still needs some time."

Just as he put down his phone, Wang Hanshan sent a message, "Professor? Are you okay? The thing about you leaving the group..."

You should care, you should care about it!

Fang Zhonggui smiled, "It's okay, I have nothing to worry about."

He is very happy now.

I'm in an exceptionally good mood.

I don't know why, but he felt that being able to hold Xu Heng in a difficult position actually gave him a sense of superiority.

He even shared with Wang Hanshan, "This student Xu Heng is like a sponge! He keeps asking questions from me! It's just to pass the time, isn't he too boring?"

"But it's all right now. The topic I gave finally stumped him."

"But I have to say, this student Xu Heng! He really has two brushes! For the fill-in-the-blank questions I gave before, he can give the correct answer in just one or two minutes..."

Wang Hanshan said weakly, "Professor Fang... that, that... don't treat student Xu Heng as a college student, he is only a sophomore..."

moment!

The complacent Fang Zhonggui was stunned.

Then his voice stopped abruptly.

Yes!

Xu Heng is just a high school student!

What's there to show off if you stump him with postgraduate entrance examination questions?

on the contrary!

It is already incredible that he has mastered the physics problems of the university!

Fang Zhonggui patted his thigh, "I misunderstood classmate Xu Heng a little bit!"

"Inadvertently, I regarded him as my student! As my gifted student! The old problem happened again! Hey..."

The Department of Physics of Peking University is full of talented people!

Fang Zhonggui took great pains to "guidance" those "thorns".

What problems haven't come up?

But looking back, using junior questions to deal with those freshman guys can make them docile.

But Xu Heng has already used the postgraduate entrance examination questions here.

"hiss……"

And Xu Heng is only a sophomore in high school now!

"call……"

Take a deep breath.

Fang Zhonggui asked himself to calm down as soon as possible.

Wang Hanshan, "Professor?"

Fang Zhonggui, "I'm fine, I'm fine."

I checked the time, 10 minutes had passed.

"I don't know if student Xu Heng is doing well now."

Wang Hanshan, "???"

Fang Zhonggui sent this question to Wang Hanshan.

After that, Wang Hanshan was also silent.

After 1 minute, he replied, "Professor, your this, this, this question...?"

Fang Zhonggui, "It's a topic I carefully prepared!"

He didn't mention the postgraduate entrance examination questions, he was thinking about Wang Hanshan's feelings.

Wang Hanshan was speechless, "!!!"

He can no longer express his inner shock in words.

Xu Heng asked Professor Fang an important question, and it was time for Professor Fang's carefully prepared questions!

!!!

It took a while for Wang Hanshan to come back to his senses, "Professor, you are not afraid of leaving a shadow on Xu Heng!"

Fang Zhonggui pressed his eyebrows slightly, thought for a while, and then said, "No! On the contrary, he should be very interested!"

"All along, he has been exposed to very simple questions, and now he will be very excited when he suddenly sees such a difficult question."

Wang Hanshan suddenly made up the knife, "Professor, the previous two questions were not easy..."

Fang Zhonggui's expression froze, "Ah..."

He is embarrassed.

"Cough, cough, cough!"