The Free Old Mentor

Jiangcheng No. 6 High School, Elite Class.

Li Dong looked at Mendel's message in the "Azure Dragon Study Group."

[Gregor Johann Mendel]: @Currently Grinding Senior-Year Problems, sir, could you explain the three-line supporting theory you just mentioned in detail?

This biology true god rarely spoke. After sending that message, he did not urge Li Dong again.

Li Dong pinched the bridge of his nose.

"As long as I can clearly explain the interaction principles between nuclear genes (R/r) and cytoplasmic genes (S/N), I should be able to give this big shot some new ideas, right?"

It was not that he did not want to explain every principle involved. He had simply spent half a class forcing himself to sort out a rough framework for the nuclear-cytoplasmic interaction model of "cytoplasmic male sterility (CMS)" that the teacher had covered. He still had not fully grasped many of the underlying molecular mechanisms.

Just as he was about to type, he suddenly felt the light beside him dim.

Li Dong instinctively looked up.

Old Chen was standing beside his desk with his hands behind his back, smiling at him.

"Holy shit!"

Li Dong jumped.

"Tea... Teacher."

He gave an awkward laugh.

Seeing that, Old Chen smiled even more kindly and waved a hand.

"Hey, go on, do your thing. I'm just taking a look."

As he spoke, Old Chen did not confiscate Li Dong's phone. Instead, he picked up the sheet of scratch paper on Li Dong's desk.

No matter how dumb Li Dong was, he could not actually follow the teacher's words and "keep playing."

He could only sit there, staring at Old Chen eagerly.

At that moment, the other students in the classroom also noticed something unusual at the back and turned to look.

Normally, no one would have had the mood to pay attention to somebody else.

But this was a newly transferred student!

The Elite Class used a brutal bottom-ranking elimination system. In every monthly exam and joint exam, the few students at the bottom of the rankings would be kicked back into the regular advanced classes, while top students from the lower classes would replace them.

So whenever a new face was parachuted into the Elite Class, everyone instinctively became wary.

Meanwhile, Old Chen held Li Dong's scratch paper, his brows drawing tighter the longer he looked.

For the first question, the time for pure rolling was t = 2v0 /(7μ_dong * g), and the final velocity was v =(5/7)*v0.

The answer was completely correct.

For the second question, he integrated the resisting torque over the circular contact patch and derived the expression for the total distance L.

That answer was also flawless.

For the third question, the expression for the precession angular velocity was Ω=(MaB)/(J*w0).

That was perfect as well.

There was nothing wrong with any of the answers, and the force diagrams were quite good too.

But!

Old Chen felt that something was missing.

He pushed up his glasses and looked through it again carefully. At last, he found what was wrong.

The calculation steps were missing!

Every part involving complicated calculations was gone!

For example, in the first question, even students in the Elite Class could barely manage to skip the steps and write down the answer directly after setting up the simple conservation of momentum equations.

But what about the second question?

That involved performing a double integral over the differential area dS=rdrdφ of a circular contact patch to obtain the rolling friction torque on a non-rigid surface!

It required tedious trigonometric substitutions and definite integrals, yet Li Dong's scratch paper only had an initial integral expression before jumping straight to the result!

The angular momentum cross-product derivation in the third question was the same. It jumped directly from the vector equation to the final scalar result.

Old Chen's eye twitched slightly.

This kid...

Mental integration? And double integrals at that?

Was his brain really that quick?

Old Chen put down the scratch paper, looked up at Li Dong, and smiled even more brightly.

"What's your name?"

Old Chen asked.

Although Li Dong felt his scalp tingle under that stare, he still answered honestly.

"Teacher, my name is Li Dong."

"Li Dong..." Old Chen muttered the name twice.

It sounded somewhat familiar...

"Oh! You're the top scorer in the province for the Huaxuan Cup semifinals!"

The quiet classroom immediately grew a little noisy.

Of course, the Elite Class students had heard Li Dong's name!

After all, the final anonymized engineering problem in the Huaxuan Cup semifinals had stumped quite a few people.

Zhao Ziwei from the neighboring Foundation Class had stumbled on that very question.

There were also a few people in the Elite Class who could solve it.

But even if they could solve it, none of them dared claim they had done better than Li Dong.

Why?

Because the person ranked second behind Li Dong on that advancement list was Qiao Fan!

That genius freshman from Chengdu No. 7 High School, treasured like a gem and free to choose between Mathematical Olympiad and Physics Olympiad!

Old Chen looked at Li Dong, growing more satisfied the longer he watched.

"Mm, not bad. You did quite well on this problem."

"Giving you this kind of problem is underselling you."

"Come with me after class. I'll show you something more fun."

At the words "more fun," the other students in the Elite Class looked at Li Dong with sympathy in their eyes.

He was done for.

Old Chen's "fun" problems were not necessarily ridiculously difficult. He would not give problems beyond someone's ability, but...

The old man loved riddles!

So everyone silently mourned, Another genius is about to be ruined by Old Chen. His Dao heart is about to shatter...

But not only did Li Dong show no fear, his eyes lit up.

"Sure!"

After all, he had the Physics Perception buff. If he could not solve a problem, that meant it involved a missing link in his knowledge. And wasn't there a teacher who looked incredibly capable right here?

This was a free old mentor.

So Li Dong hurriedly said,

"Thank you, Teacher! Thank you!"

That enthusiastic and sincere reaction left Old Chen standing there in a daze.

How many years had it been?

Whenever he told students to come to his office to do "fun problems," which of those little brats had not worn a miserable expression?

Yet today... he had actually received such sincere thanks?

Old Chen's gaze at Li Dong became even more "kind."

"Ring-ring-ring!"

As soon as the dismissal bell rang, Li Dong eagerly followed Old Chen out of the classroom.

The moment the two left, the classroom erupted.

Although these Elite Class top students normally did not gossip much, today's news was simply too big.

This was someone fierce enough to beat Chengdu's Qiao Fan!

Before class had ended, everyone had seen Li Dong seemingly exchange a few words with Mi Ge. A few boys then went over to Mi Ge.

"Hey, Mi Ge, how do you know that Li Dong?"

"His physics is so insanely good. What about his other subjects? Do you know anything about his background?"

Surrounded by several second- and third-year upperclassmen, Mi Ge answered truthfully.

"Oh, he's my sister's classmate. As for his other subjects..."

"My sister said his Chinese and English seem pretty average. He's the type who barely passes."

"Average?"

The crowd looked at one another, their expressions turning strange.

The Elite Class was not somewhere you could enter with just one specialty! It demanded well-rounded students with no weak subjects.

Because once these students failed in their competition push, their fallback was the college entrance exam.

What exactly did it mean for this Li Dong to enter the Elite Class?

Of course, they did not know about the research fund that followed the person.