Super academic master: start with low adjustment scores!

"Why is it 88 points again?"

"Or is it..."

"I have to control the score to 88 in all four competitions?"

"If that's the case, there are also benefits. At least it won't attract too much attention. After all, it's impossible to be the first in all the subjects."

Jiangnan thought secretly.

Then he picked up the physics test paper and glanced at it.

Five multiple-choice questions.

Each question is 6 points, a total of 30 points.

Five fill-in-the-blank questions.

Each question is 6 points, a total of 30 points.

Two essay questions.

Each question is 20 points, a total of 40 points.

And he needs to control the score to 88 points. The easiest way is to get one multiple-choice question and one fill-in-the-blank question wrong.

Yeah!

Perfect.

After making up his mind, Jiangnan started working directly.

The first question.

"As shown in the figure, a light marble with a stiffness coefficient of h is fixed on the ceiling at the top and connected to a small ball with a mass of m at the bottom. The equilibrium position 0 of the small ball is taken as the origin of the coordinate system."

"The positive direction of the x-axis is downward. If the origin of the coordinate system is taken as the zero point of the system potential energy, then when the small ball is at the position of coordinate x0, the total potential energy of the system is..."

A: 1/2kxo^2-mgxo.

B: 1/2k(xo+mg/k)^2-mgxo.

C: 1/2k(xo+mg/k)^2.

D: 1/2kxo^2.

...

Jiangnan: "..."

Somewhat speechless.

Just because...

He always felt that the person who made the question was insulting his IQ.

Such a simple question.

Is it really necessary to take the test?

And it's a so-called competition?

He chose B without even thinking about it.

As for multiple choice?

This obviously does not have multiple choice.

And the problem-solving process?

Is there really a problem-solving process?

Is there really someone who can't even solve such a problem?

If there is, then you can only go to the hospital for a check-up to see if there is a problem with your IQ.

One question after another.

Almost in the blink of an eye.

Jiangnan finished the five multiple-choice questions.

Uh!

Okay!

It seems that he did one more.

In order to control the score of 88, he had to erase the last multiple-choice question and deliberately fill in a wrong answer.

Then...

There are four fill-in-the-blank questions.

Same!

He almost did it instinctively.

He got all the fill-in-the-blank questions right in one breath.

So he had to do the same as before, erasing a question in reverse and replacing it with a wrong answer.

Oh!

This damn instinct!

It's all because his physics level is too high and his physics foundation is too strong. It's really a little sad.

But...

The 12 points that should be deducted have been dealt with.

The next two questions will be easier to answer.

Question 11 (20 points).

"As shown in the figure, a rectangular plate with a mass of M and a sufficient length is stationary on a smooth horizontal ground.

The left end of the plate is connected to a horizontal light spring with a stiffness coefficient of h, and the other end of the spring is fixed to the wall; there is a small block with a mass of m on the plate.

At time 1=0, the plate is stationary.

And the small block starts to move to the right at a speed of n.

It is known that the sliding friction coefficient between the small block and the plate is μ, and the magnitude of the gravitational acceleration is g.

(1) Prove that: During the process of the small block sliding to the right relative to the plate, the motion of the plate is a simple harmonic motion. Calculate the amplitude and frequency (period) of the simple harmonic motion.

(2) If the plate starts to move from time t=0 to a quarter of a cycle, the small block happens to be stationary relative to the plate for the first time, calculate...

(i) The value of the initial velocity of the small block.

(ii) The heat generated by the plate during the process of moving a quarter of a cycle."

...

Jiangnan looked carefully for three seconds.

Then...

He started to solve the problem directly.

He didn't even need a draft paper.

Just because...

This question looks very long.

But it couldn't be simpler.

It's nothing more than examining friction, simple harmonic motion, and energy conservation.

It can't be said to be outdated.

It can only be said that it has been done to death.

Solution.

"1: When the small object slides to the right relative to the plate, the sliding friction force on the plate is...

f=μmg.

Direction to the right.

For the plate, according to Newton's second law,...

f-kx=Ma.

In the formula, x is the extension of the spring, and a is the acceleration of the plate (positive to the right).

Let x'=x-umg/k.

From ①②③, we get -kx'=Na.

It can be seen..."

"2..."

"..."

With almost no pause.

He solved the two questions of the question in one breath.

Then...

It was the last question.

I have to say.

This final question is a little interesting.

Unlike the previous ones, you can see the answer at a glance.Just like giving away points, even a fool can pick it up.

And this 12th question.

Jiangnan thought about it for a while.

Then...

He had an idea.

Half a minute later.

He finished writing and called it a day.

Jiangnan stood up and handed in the paper.

"Jiangnan?"

The invigilator looked at the name on the paper and frowned instantly, "Are you the Jiangnan from No. 3 Middle School who won the first place in the city in the Mathematical Olympiad two days ago?"

"It's only been a few minutes since the exam, and you can't do it. Are you just handing in the paper and giving up the exam?"

"..."

As for Jiangnan.

The invigilator of No. 1 Middle School naturally knew about it.

After all...

Jiangnan's name has been very popular these two days.

But...

Jiangnan is good at the Mathematical Olympiad.

It doesn't mean that he is also good at physics.

As for the so-called top scholar, it is even more of a joke. Most people in No. 1 Middle School don't believe it, and he naturally doesn't believe it either.

Especially now that the physics competition has just begun, Jiangnan has to hand in his paper, which is an obvious proof.

He doesn't even need to look at the test paper.

He can conclude that.

Jiangnan is a poor student in physics.

There are twelve questions out of a hundred points, and Jiangnan will probably get zero points, and can't answer any of them.

That is the so-called...

Giving up the exam.

In response to this.

Jiangnan frowned slightly and said, "Teacher, I didn't give up the exam, I just finished and handed in the paper in advance."

After that!

He left directly.

There is another chemistry competition in the afternoon.

Today the weather is good and sunny.

If he has time, he also wants to go to the lawn to bask in the sun, take a rest, and recharge his energy... Recharge his energy.

"Hmph!"

"Arrogant and conceited, don't know what you mean."

"I want to see how many points you can get."

The invigilator didn't have a good impression of Jiangnan to begin with, and this time, he was even more disgusted.

However...

When he picked up Jiangnan's paper to check, he was stunned for a moment, just like a certain invigilator before.

"This..."

"It's not a blank paper?"

"Did he really finish it?"

"How is it possible?"

"It's only been a few minutes since the exam started!"

"Even if he filled it in randomly, it can't be so fast! Besides... it doesn't look like random writing???"

"Huh?"

"It's really not random writing. He got the first question right, the second question right, and the third question right..."

"..."