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Chapter 14: Chapter 14: Jiang Yang: I Don’t Quite Understand

The Physics Ossai—its official name is the National High School Physics Competition.

It’s divided into a preliminary round, a semi-final, and a final.

And the test paper Li Dong was looking at was from a previous year’s Ossai preliminary round.

Li Dong took a deep breath and, out of habit, first scanned the score distribution on the test.

Based on his experience with regular college entrance exam papers, physics was usually worth 100 or 110 points total.

But now...

[Total Score: 400 points]

[Time Limit: 2 hours]

”400 points?”

Li Dong was inwardly stunned.

’That’s more than an entire comprehensive science exam.’

Looking at the number of questions, there were 26 in total.

The first 15 were multiple-choice, including single-answer and multiple-answer questions, with each worth over 6 points.

Following those were 5 fill-in-the-blank questions and 6 major calculation problems.

’So this is the so-called intensity of the Ossai.’

Although Li Dong was a little surprised, he was more filled with an eager excitement.

For the past few days, he’d been like a man with a hammer, seeing everything as a nail he wanted to pound. This was perfect.

He looked at the first multiple-choice question.

Usually, the first question is a freebie, meant to help the test-taker settle their nerves.

But when Li Dong read the question clearly, his eyebrows still twitched slightly.

[1. As shown in the figure, a semi-cylinder with radius R is fixed on a horizontal surface. A small ball of mass m is on top of it. The ball starts sliding down from the highest point of the cylinder from a state of rest. Ignore all friction. When the ball separates from the surface of the cylinder, what is its vertical drop height, h?]

At first glance, this problem seemed like a standard high school circular motion model.

A typical high school senior might just plug everything into the centripetal force formula: mg - N = mv²/R.

But there was a catch.

The problem didn’t provide the specific angle of separation.

So, the test-taker needed to establish their own polar coordinate system.

Or, they could solve for the critical condition by combining the law of conservation of energy with Newton’s second law.

’Interesting. A challenge right off the bat.’

If this question were on a high school physics exam, it would definitely be the final, most difficult multiple-choice question.

But on an Ossai paper, it was only the first question.

However...

Li Dong smiled happily, like Ximen Qing meeting Pan Jinlian.

’For the me right now, this kind of rigid body motion model couldn’t be simpler.’

He didn’t even need to draw a force analysis diagram on his scratch paper.

The [Physical Perception] buff gave him a clear picture in his mind.

The ball began to slide, potential energy converting into kinetic energy, the normal force rapidly decreasing as the angle changed...

”Conservation of Energy: mgh = 1/2mv²”

”Centripetal Force Equation: mg(R−h)/R = mv²/R”

Combining the two equations:

2gh = g(R−h)

3h = R

h = 1/3R

In just ten seconds, Li Dong had checked off option C.

The office was frighteningly quiet, with only the faint RUSTLE of pen tips moving across scratch paper audible.

Although the surrounding teachers were all busy with their own work, their gazes drifted over from time to time.

Jiang Yang stood behind Li Dong, watching his problem-solving speed, his expression slowly shifting from initial anticipation to confusion.

Although he was a physics teacher, to be honest, he was just an ordinary teacher who had graduated from a second-tier normal university.

Teaching regular high school physics was no problem for him.

But these were Ossai problems!

’If I were to solve that first problem,’ he thought, ’I’d have to draw a diagram, set up a system of equations, and struggle with it for at least two or three minutes, right?’

But Li Dong? He just read the question and checked the answer?

’This kid... he’s not just guessing, is he?’

Jiang Yang muttered to himself. He had only ever heard of people solving problems like this; he’d never actually seen it.

But Old Yang, standing on the other side, found his eyes growing brighter and brighter the longer he watched.

He was a top student from Capital University, and his foundation from back then was still solid.

Although he didn’t teach physics, math and physics are intertwined, and he could understand the logic involved.

He saw Li Dong working on a problem about ”a charged particle’s motion in a non-uniform magnetic field.” Li Dong’s pen tip traced a helix in the air, and then he directly wrote down a differential equation for the radius of curvature.

r = mv / qB(x)

That equation was from University Physics!

’This kid...’ Waves of shock crashed through Old Yang’s mind.

If his performance on the previous math problems could be called a coincidence, then instantly solving several consecutive problems now was an absolute demonstration of his true ability.

The way Old Yang looked at Li Dong changed.

In contrast, Jiang Yang seemed a bit restless.

He couldn’t understand Li Dong’s skipped steps, nor did he know if the answers Li Dong chose were correct.

The feeling made him a little flustered.

’This won’t do. I need to get someone who knows what they’re doing to take a look.’

With that thought, Jiang Yang turned and slipped out of the office.

...

Inside the principal’s office.

The room was thick with smoke.

The head of the physics department, Zheng Hua, was sitting on the sofa with a troubled expression.

”Principal Wang, it’s really not that I’m being uncooperative,”

Zheng Hua said with a sigh.

”You know the situation at our Seventh Middle School. All the promising sprouts have been cherry-picked and taken away by Sixth Middle School and First High School.”

”The remaining students have to prepare for the college entrance exams. You want me to find someone to participate in the competition now? Where am I supposed to find anyone? I can’t just force them, can I?”

Principal Wang, sitting behind his desk, also wore a helpless expression.

”Old Zheng, I know your difficulties, but this is a directive sent down directly from the Municipal Education Bureau. They say we need to focus on comprehensive development, not just the college entrance exams.”

”Don’t put too much pressure on yourself. We’re not aiming for any awards. As long as someone goes, fills out the paper, and doesn’t hand in a blank test, that’s good enough. We just don’t want to look too bad.”

Just as the two were venting their frustrations,

BAM!

The office door was thrown open.

Principal Wang and Zheng Hua were both startled, their brows furrowing in unison.

”Xiaojiang? Don’t you know how to knock before entering?”

Principal Wang said, somewhat displeased.

Jiang Yang then realized how hasty he’d been and quickly apologized.

”Ah, sorry, Principal Wang. I... I have urgent business with Leader Zheng.”

Zheng Hua looked at the panting Jiang Yang, and his heart skipped a beat.

”What’s wrong? Did some students get into a fight?”

You have to understand, not only was he the head of the physics department, but he was also the Dean of Students at Seventh Middle School.

Fights between students happened from time to time at Seventh Middle School; as long as there were no serious consequences, it was fine.

But seeing Jiang Yang in such a hurry was why he asked.

”No, no,” Jiang Yang quickly waved his hands.

”Leader Zheng, you... you have to come to the office and see. There’s a student doing that Ossai preliminary paper, and I... I can’t really follow what he’s doing.”

When Zheng Hua heard this, his brow furrowed even more tightly.

”Xiaojiang, do you have too much time on your hands? I was just talking to Principal Wang about this. Why would you give an Ossai paper to a student?”

He sighed and said in a grave, heartfelt tone,

”I know you want to complete the task, but you can’t just be reckless.”

”Which student is it? Chen Yue? Misha? Or Jiang Yizhou?”

Those three were considered the best physics students in their year, but in Zheng Hua’s opinion, having them do Ossai problems would be a complete waste of time.

”It’s none of them.”

”It’s a student named Li Dong.”

Jiang Yang said quickly.

”Li Dong?”

Zheng Hua searched his memory but came up with nothing.

”Never heard of him.”

Jiang Yang then recounted how Li Dong had used the Microelement Method to solve the chain problem.

”What? The Microelement Method? The Momentum Theorem?”

Zheng Hua’s expression changed.

As the head of the physics department, his skill level was naturally much higher than Jiang Yang’s.

He also knew about the problem Jiang Yang had gotten wrong, so he understood the true caliber of that chain problem.

If a high school student could skillfully use Calculus to solve a variable-mass problem, that absolutely couldn’t be explained away as a ”coincidence.”

”Let’s go! We’ll go take a look!”

Without another word, Zheng Hua stood up and headed for the door.

Principal Wang’s work was administrative, so he had no concept of things like the Microelement Method. He just wanted to get the task from his superiors completed quickly, so he hastily reminded him,

”Old Zheng, don’t forget about the headcount!”