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

"Rupert's Tears" are formed when melted glass is naturally dropped into water by gravity.

Qin Fangming, "In 1994, S. Chandrasekran of Purdue University and M. M. Chaudhry of Cambridge University observed the teardrop fragmentation process with high-speed photography."

"They concluded through experiments that the surface of the glass teardrop has a strong compressive stress, while the inside has a strong tensile stress, so the teardrop is in an unstable equilibrium state, and the tail is seven inches the size of Rupert's tear. .”

"..."

Qin Fangming talked a lot, probably to cover up his embarrassment.

"Studies have shown that the Rupert's tear glass drip head shows a compressive stress as high as 700 MPa, which is nearly 7000 times the atmospheric pressure..."

Xu Heng, "Uh... teacher time is limited, let's talk about the topic!"

"What you want to tell me is not just these theoretical knowledge?"

Qin Fangming smiled bitterly, "Uh... let's do it!"

Xu Heng, "The reason why this Rupert's force has these characteristics is firstly related to stress, which is its internal force."

"There is no force acting on the inside of ordinary glass!"

"But there are Rupert's tears. The reason is that after the glass melts, it drips into the water to form a water drop."

"In the beginning, when this thing was dropped into water, the temperature of the glass was very high, but the temperature of the water was not high, so once it was in contact, the outer glass of the glass would cool down rapidly when it encountered water."

"..."

"So the inner volume will shrink..."

Xu Heng didn't give Qin Fangming a chance either, he explained it very detailed and specific.

He didn't care whether Qin Fang knew it or not, anyway, he said what he wanted to say.

"The outside is the compressive stress, and the inside is the tensile stress..."

These knowledge points are not learned in today's high schools, which is obviously beyond the outline.

The corners of Qin Fangming's eyes twitched fiercely.

After so many years of being a physics teacher, his interest has been wiped out.

At the beginning, when he first became a physics teacher, he was full of enthusiasm and had a lot of thoughts.

But gradually, he returned to ordinary, and gradually got up step by step.

Over time, he felt that things other than lesson preparation were beyond the outline, and he no longer shared or interacted with his classmates...

He believes that there is no need to talk about those super-class things!

After all... don't take the exam!

"Here, it will involve the production of tempered glass..."

Xu Heng's knowledge points are too dense!

When Qin Fangming was reflecting on himself, he was already dumbfounded.

Although Xu Heng was talking about Rupert's Tears, he was even familiar with making tempered glass.

Xu Heng's knowledge reserves made Qin Fangming and even other physics teachers in the office feel ashamed.

Not only these knowledge points, Xu Yongheng also mentioned the tempered glass of the bank, why is it so thick?

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·??????????????

"Multiple layers of tempered glass with glue!"

"This glue is tempered laminated glass, which can greatly improve the strength of tempered glass."

"..."

This is where to learn a thing!

This obviously expands a lot of dense knowledge points!

After Xu Heng finished speaking, "Teacher, are you OK? Can I go back?"

Only then did Qin Fangming come back to his senses, and was just about to speak.

The principal came over in a panic.

"Student Xu Heng! I've been looking for you! Come here! Come here!"

It doesn't matter what Qin Fangming and the others are looking for with Xu Heng!

The principal looked nervous and frowned, and led Xu Heng all the way to the principal's office.

Then he closed the door, even barred it.

"Huhuhu..."

The principal held the phone in his hand, his eyes widened, and he just stared at Xu Heng.

Xu Heng was very indifferent, "Principal, what's the matter? What happened? Just tell me if you have anything to say?"

Principal, "Hiss... hiss... student Xu Heng, you, do you know?"

Xu Heng, "???"

She spread her hands, "How would I know if you didn't tell me?"

The headmaster took a deep breath and took several times to calm himself down. "The director of the education bureau of the nineteen provinces has been negotiating with the state department for a long time because of you!"

"For you, for your participation in the [-]th Provincial Federation! They fight hard!"

"It is said that nineteen directors of the Education Bureau were interviewed together!"

"As a result, I don't know yet!"

"This has been talked about for more than two hours!"

...... 0

Xu Heng, "???"

"So...it's not that Dean Nie doesn't agree with them, but that the state doesn't let them mess around at all, right?"

The headmaster patted his thigh, "That's right! The Nineteenth School Joint Examination! This includes nearly half of the future high school entrance examination students, which has never been done before!"

"They are negotiating with the country!"

"I dare not even think about it! Xu Heng! They are doing this for you! For you, they are negotiating with the country!"

Xu Heng immediately waved his hand, "Don't, don't, don't! Principal, don't let me put a high hat on you, I don't deserve it! I'm just a student."

"At the end of the day, they still think for themselves."

indeed!

It's the directors of these provincial education bureaus who think for themselves!

Of course, they think a lot!

The reason why they want to organize this [-]-province joint exam is to let the candidates realize the difficulty of the college entrance examination!

At the same time, they also want to warn all candidates that the college entrance examination is not just "this way"!

No, only "this"!

College entrance examination!

It can also feel different!

Do not break or stand!

In the mock exam before the college entrance examination, it is very important for the college entrance examination to allow candidates to position themselves more clearly!

Only in this way can each candidate improve himself!

It even turns quantitative changes into qualitative changes.

It was because of Xu Heng that they organized the [-] provinces entrance examination this time!

But in fact, the appearance of Xu Heng gave them hope!

See, Xu Heng should be passed to improve the overall scores of all college entrance examination candidates, and...don't study hard, don't study badly, don't talk about it on paper, but integrate learning into life.

In life, experience, learn, and improve!

Xu Heng's previous monthly exam papers let them see this!

Therefore, in the conference room of the national department, the nineteen provincial directors of education insisted on this.

"Leader, the nineteen of us are not in a hothead."

"Although we haven't discussed it together, our ideas coincide with each other!"

"When one of us spoke up, we realized we were all on the same page!"

"And Xu Heng is something that can turn our ideas into reality!"

"Our [-]th province's entrance exam this time..."

"..."

The leader said with a blank expression, "Stop! This is not what we are discussing now. Everyone, you should be very clear about how many students are involved in the joint entrance examination of the [-] provinces, how many millions?"

"How many people take the college entrance examination?"

"It's almost halfway..."

The leaders emphasized the college entrance examination!

It is the scale of the exam. As for their good intentions, the leader asked, "Why do we have to have nineteen provinces together, seven provinces, eight provinces, isn't it all possible?"

"Everyone! Look at things, not just in front of your eyes!"

"Besides, all of you are a little too strong!"

"..."

"Are you guys joking? Must be Xu Heng?"

"Is there no one who can replace him?"

The nineteen spoke in unison, "No one can!"

"!!!"Four.

Chapter 327

When Xu Heng came back from the principal's office, he looked calm.

The whole group looked at Xu Heng.

Xu Heng, "???"

Sitting back in her seat, Yue Pingting immediately came over.

Xu Heng, "What's wrong? Why are you looking at me like that?"

Yue Pingting explained, "Before the principal came to see you, he was in such a hurry, I've never seen the principal so flustered!"

Xu Heng raised his eyebrows and asked, "How flustered?"

Yue Pingting, "I was so flustered that I saw that the hair on the principal's head was a wig... The wig almost flew up..."

Geek!

In the next second, Xu Heng couldn't hold back, "Puff...hahaha...!"

wig?

Yue Pingting, you girl, you did it on purpose!

"Hahaha……"

Yue Pingting's face turned dark, and she stomped her feet angrily.

"Xu Heng! Don't laugh! Don't laugh!"

"You are too much..."

"You, you laughed at the principal, you..."