Chapter One Hundred and Seven

It's May 1st, Labor Day.

This year's Labor Day can be described as ill-fated.

Because on May Day, it happened to be stuck on Wednesday, a day that could not be up or down.

Therefore, according to the original arrangement, Labor Day is only on May 1.

It's just that fortunately, a reporter's sister spoke up, and after discussion, the big guy above extended the May Day holiday to four days.

According to national regulations, May Day is a four-day holiday!

But according to the school regulations of Haicheng No. 1 Middle School, for senior high school graduates, May Day is only one day.

Moreover, it is also the last opportunity to have a holiday before the college entrance examination.

The next vacation will have to wait until after the college entrance examination.

According to the original words of the head teacher Ma Qiumei, if you want to take a holiday and go around, no problem, stick to it for another month.

After a month, you have almost three months of vacation time to do whatever you want.

Whether you want to sleep until you wake up naturally, stay up late at an internet café to play games, or go on a trip, no one will restrain you.

But in this last month, we must be strict with ourselves and do not allow even the slightest slack!

…………

May 1 is also the opening day of the 34th National Physics Competition for Middle School Students.

Su Xi is also on a business trip abroad.

Gu Lu, as Su Ling's competition tutor, personally accompanied Su Ling to participate in the competition.

Like the Mathematics League, the Physics Competition is also held nationwide, but the examinations and awards are given in different provinces.

Unlike the Math League, the Physics Competition has not only a written part, but also an experimental part.

The same out of three hundred points.

200 points for the written test and 100 points for the experiment!

The written test paper is a unified proposition by the whole country.

The experimental topics are independently proposed by each province according to their own conditions.

In general, the lab questions are not difficult.

The examination is about the use and operation of physics experiment equipment, and does not examine too much theoretical knowledge.

Therefore, as long as you make sufficient preparations in advance and have a clear understanding of the operation of all experimental equipment, it is not difficult to get a score of more than 90 points in this link.

The most difficult part is the written part.

Like the second test of the Mathematics League, the written test of the Physics Competition does not choose to fill in the blanks, and it is all big questions.

Moreover, it is a whole eight big questions.

The fields of study cover mechanics, electromagnetism, optics, heat, and modern physics.

The difficulty of each question is more than one grade higher than the difficulty of the questions in the physics test paper of the college entrance examination.

…………

Gu Lu and Su Ling arrived in Quancheng on the evening of April 30.

Looking for a hotel near the examination room, Gu Lu ordered two rooms and settled down temporarily.

The next day, the 34th National Physics Competition for Middle School Students officially opened.

In terms of the number of participants, the physics competition is naturally not as large as the number of students in the mathematics league.

However, in terms of the quality of candidates, it is not inferior to the National Middle School Mathematics League.

In this year's CPhO, more than 3,000 candidates from the province participated in the competition.

The provincial team quota is only about five or six people per year.

Written test in the morning and experiment in the afternoon.

Under the teaching building used for the exam, Gu Lu waved to Su Ling, who was about to walk into the examination room.

"Come on!"

"Hmm!" Su Ling's little face tightened, clenched his little hand, and nodded heavily at Gu Lu.

Then he turned around and walked into the exam room with a firm step.

At nine o'clock, the written test officially began.

Su Ling's eyes looked at the few confident and high-spirited figures in the examination room with some apprehension.

Compared with the few people who were full of confidence, Su Ling was obviously a little lacking in confidence.

After all, Su Ling's preparation time for CPhO was only two months.

The rest of the candidates, at least during the winter vacation, have already begun to prepare for CPhO.

The bold words promised before seemed to have been left behind by Su Ling.

At this time, Su Ling, like a little white rabbit mixed into the wolves, curled up in the corner, trembling.

The bell rings for the start of the exam.

The invigilator distributes the test papers.

Su Ling, who got the test paper, was a little uneasy in his apprehension, and his eyes swept over the eight questions on the test paper in turn.

How can the first question be so simple?

Hmm? Will anyone come up with such a non-difficult question as the second question?

I've done a similar question to the third question, but the data is different.

Hmph, just the fourth question, I still want to Miss Ben!

…………

Su Ling's big eyes gradually curved up, narrowing into the shape of a crescent moon.

"It's very simple!" Su Ling murmured in a low voice with a sweet smile on the corner of his mouth.

Just now, she was scaring herself.

Sure enough, just like what Mr. Gu said to himself last night, as long as he can play normally, this national physics competition for middle school students can be passed smoothly.

So, then, it's my turn to perform!

Su Ling took out a carbon pen from the pencil case, pulled out the cap, and the tip of the pen paused in mid-air, thinking about the solution to the problem.

The first question is mechanics.

It is also the easiest of the eight questions.

[A hemispherical surface with a radius of R and a smooth inner side is fixed to the ground, with the opening horizontal and facing upwards.] A small slider obtains the horizontal velocity along the spherical surface at the highest point of the inner hemispherical surface, and its magnitude is v0(v0≠0), and the maximum velocity that the slider may reach in the whole motion process is obtained. The magnitude of the gravitational acceleration is g. 】

A question to be sent!

Not to mention that it is a competitive candidate, even if you ask a random high school student to come over, it will not be a problem to complete this question at all.

Su Ling shook his little head and thought quickly while listing formulas on scratch paper.

"Taking the slider and the earth as a system, it conserves mechanical energy during the whole motion, and when the slider moves along the inside of the hemispherical plane, its velocity v can be decomposed into the horizontal component vφ and the vertical component vθ. ”

“…… Next, from the conservation of mechanical energy, it can be obtained that 2mv0^2=-mgRsinθ+1/2mvφ^2+1/2mvθ^2. Then according to the law of conservation of angular momentum, mv0R=mvφRcosθ. ”

“…… To sum up, Vmax=vφ^2=1/2(v0^2+v0^4+16g^2R^2)!"

Question 1, that's it!

Except that there are a little more formulas, there is not much difference from ordinary high school physics problems.

This is Su Ling's subjective feeling.

The second question is a question of electromagnetism.

[The two poles of the parallel plate capacitor are located in the plane of z=±d/2, and the capacitor is not charged at first, and the whole device is in a uniform magnetic field. The magnitude of the magnetic induction intensity is B, and the direction is negative along the x-axis, as shown in the figure. 】

→_→ pretend to have a diagram here

[1. In the capacitor reference frame S, only the magnetic field exists, and at a constant velocity (0, v, 0) along the positive direction of the y-axis, relative to the capacitor......]

[2. Now let the electrically neutral liquid (insulator) with dielectric constant e flow at a constant speed between the two pole plates of the parallel plate capacitor, with a flow velocity of v, and the direction is positive along the y-axis, in a reference frame where the liquid is stationary......]

Simple, outrageously simple, so simple that it's hard to accept.

How can such a simple question reflect the gap between me and other candidates?

In such a series of exclamations, in less than two hours, Su Ling completed the answer to all eight questions.

…………

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