I just want to be a quiet scholar

Chapter 77: Secretly Observing
Laboratory building, the entrance to the back door of No. 1 Physics Laboratory.

Shen Qi stood outside the back door, observing secretly through the glass embedded in the door.

In the physics laboratory, the heads of scientists such as Newton, Kepler, Faraday, and Watt are hung on the walls, and four big characters hang above the blackboard: the unity of knowledge and action.

The layout of the laboratory is different from that of the classrooms in the teaching building. The desks are replaced by long experimental benches. More than a dozen students sit behind the experimental benches. Collision test instruments, timers, heavy hammers, etc.

But no one operated any of the experimental instruments. The students held their cheeks or raised their eyebrows, staring at the blackboard in front of them, with pens and paper in front of them.

A schematic diagram of a water wave was drawn on the blackboard, with chalk writing:

"Water waves are not strictly transverse or longitudinal waves, because the water motion on the surface is neither perpendicular nor parallel to the direction of the wave speed, but a superposition of the two."

"When the water is deep enough, each point on the surface makes a circular motion in place. Let the amplitude be A, the wavelength be λ, and the period be T."

"Assuming A<<λ, and the reference frame moving with the waveform sees a steady flow velocity, what is the flow velocity at the highest and lowest points of the wave?"

"Ignoring surface tension and friction loss, let the density of water be ρ, the acceleration of gravity be g, and consider the conservation of energy, please prove that the wavelength and period satisfy the relationship: λ=gT^2/2π."

Clearly, what was written on the blackboard was a physics problem.

The physics questions are quite long-winded, and there are a lot of text descriptions.

The first question is not difficult. The flow velocity uv and u+v of the highest and lowest points have been written on the blackboard.

The proof for the second question has not yet been written.

On one side of the blackboard, a young woman stood by the window. She wore rimless glasses and put one hand on the windowsill, looking out of the window.

Shen Qi, who was secretly observing at the back door of the classroom, had a preliminary judgment that this woman should be the teacher of the competition team, and more than a dozen students, including Lin Xingyu, were team members.The female teacher gave a physics problem to the team members. Is this what Lin Xingyu calls training?

In Shen Qi's impression, the discipline competitions of physics, chemistry, and biology should include experimental links. What is the difference between pure quizzes and math competitions?It's just that the subject matter is different.

Shen Qi continued to observe secretly, this female teacher who leads the competition team is not very old, and it is possible to be between 25 and 35 years old. There are not many female teachers who lead the competition. Let's see how strong she is.

The female teacher turned around to face the players offstage, and snapped her fingers crisply: "Who came to the stage to write the proof process for the second question?"

Lin Xingyu raised his hand.

"Okay, Lin Xingyu came to the stage to prove it." The female teacher said.

Lin Xingyu came to the stage and used chalk to write out the proof process:

1/2△mv1^2+△mg2A+p0△V=1/2△mv2^2+p0△V
After simplification:

λ=gT^2/2π
certified
After Lin Xingyu finished writing, he looked at the female teacher.

Snapped.

The female teacher snapped her fingers again: "Smart."

Lin Xingyu was greatly encouraged: "Thank you Teacher Mu for your affirmation."

Oh, Mr. Mu.Shen Qi learned the surname of the female teacher of the competition team. Where did this teacher Mu come from? Why am I not impressed?On second thought, for more than half a year, I have been competing in mathematics competitions at home and abroad, and I went to Yanda Golden Autumn Camp for training.

Lin Xingyu returned to his seat cheerfully, and looked at Teacher Mu with admiration. He had the same expression when he saw Shen Qi just now.

Teacher Mu looked like a learned person. She wore glasses and had short short hair, and then she asked the question:

"There is a type of submarine that uses electromagnetic propulsion instead of the propeller, and water flows through the propulsion pipe, regardless of the viscous resistance between the water flow in the pipe and the pipe wall and water."

"There is a cuboid region in the pipe, the cross-sectional area of ​​this region is the same as that of the water inlet, and the size is a × b × c, in which a stable magnetic field B is generated by the superconducting magnet, along the b direction, there is a piece on the upper and lower sides. Electrodes the size of a×b, into the DC power supply.”

"Assuming that the current exists only in this cuboid region and is uniform, the steady state current size is I, the seawater density is ρ1, and the seawater resistance is ρ."

"Assume that the pressure at the water inlet of the submarine after steady flow is p1, the pressure at the water outlet is p2, the area of ​​the water inlet is S1 = b × c, and the area of ​​the water outlet is s2."

"1. After obtaining the stable flow, take the submarine as the frame of reference, the flow velocity v1 and v2 at the inlet and outlet."

"2. Calculate the power of the DC power supply after the steady flow."

Teacher Mu's chalk fonts are strong and powerful, and her hands are fast. She finally drew a schematic diagram of the structure of the submarine's propeller, and the question was completed.

"This question is adapted from a certain year's college entrance examination physics test in eastern Zhejiang Province. I will give you 10 minutes to think and write drafts." After Mr. Mu finished speaking, he walked towards the front door of the No. 1 Physics Laboratory.

Shen Qi was reviewing the problem outside the back door. This problem is not difficult, but there are many physical knowledge points that need to be comprehensively applied. Electricity, electromagnetism, mechanics, energy and momentum have to be gathered up, using pure high school physics knowledge to solve. There is no problem with this question.

For most people, high school career is the most knowledgeable stage in their life, with good memory, quick reactions, quick thinking, and the little prince of knowledge and the little queen of problem solving are not uncommon.

There are generally two trends after high school, more erudite, or more mediocre.

The former is less, the latter is more.

Youth is short and precious.

Why not pretend to be young.

There is no shop after this village.

Time is not forgiving, pretending to fight for the day and night.

The characteristics of physics problems are that ideas dominate everything, supplemented by necessary calculations. In terms of calculation volume, most branches of physics cannot be compared with mathematics.

However, it is difficult to make a difference in physics only by relying on pure mathematical calculation ability and without understanding many formulas and principles of physics.Ou Ye's calculation Ji can only major in mathematics, while Shen Qi can double xiu.

In a very short period of time, Shen Qi had already figured out the first question of this submarine problem, and the amount of calculation was not large.

At this time, Teacher Mu walked out of the front door of the physics laboratory. As soon as she went out, she found a boy outside the back door sneaking a sneak peek into the laboratory.

Teacher Mu didn't show any signs of speaking. She went downstairs from the corridor near the front door. After reaching the end of the second floor, she went up to the third floor again, and slowly walked back to Shen Qi.

Shen Qi, who was concentrating on the second question about the submarine, didn't notice it, and a female teacher stood behind him.

"Is it interesting?" Teacher Mu said softly behind Shen Qi.

"It doesn't make any sense... eh?" Shen Qi turned his head suddenly, what the hell, is this Teacher Mu a ghost, why is there no sound when he walks?
Teacher Mu looked at Shen Qi carefully, and said after a while: "IMO full score champion Shen Qi, why are you eavesdropping on my physics class?"

"Hello, Teacher Mu, I'm just passing by." Shen Qi quickly regained his composure.

(End of this chapter)