"System, are there any questions that can improve my current physics level?"

"The host has now mastered the knowledge points and sorted out the corresponding physics test questions. You can spend 1 point to purchase 10 test questions."

"This test question made of gold actually costs 0.1 points each...

Okay, then give me 70 test questions."

Although the test questions provided by the Tucao system were expensive, Zhao Xiancai still spent 7 points to purchase them. After all, if he bought the test questions from the system, even if he didn't know how to do it, he would still get a free tutor.

"For Chinese, let's listen carefully in the next class, and do the 70 system-wide test questions first."

After purchasing the test questions, Zhao Xiancai said to himself while doing the questions.

"As shown in the figure, there is a deep vertical well. The cross-section of the well is a circle, the radius is R, and the well wall is smooth. A small ball is thrown from one side of the well mouth at a horizontal speed V0, and the well is in contact with the well.

The wall collides and is rebounded at the original speed after the collision. Find the depth of the n-th collision between the ball and the well wall."

After reading the question, Zhao Xiancai started writing the question on the draft paper.

"Because the distance traveled by the ball in the horizontal direction Sx=2nR, the time taken t=Sx/v0=2nR/v0... So the depth when the ball collides with the well wall for the nth time is 2n2R2g/v20."

After writing down the problem-solving process on the scratch paper, Zhao Xiancai was a little disdainful of the systematic questions.

"That's it? I've spent a lot of money on these 7 points."

Zhao Xiancai continued to answer the second question while thinking about it.

Although the difficulty of the second and third questions was gradually increasing, Zhao Xiancai could still handle it.

But starting from the sixth question, Zhao Xiancai started scratching his head and biting his pen.

"get out of class is over."

Zhao Xiancai was still thinking about the sixth question until the Chinese class was over.

"What are you thinking about?"

Cheng Zhijun, who had not seen Zhao Xiancai looking like this for a while, put his head over after the Chinese class to see what Zhao Xiancai was writing.

But Zhao Xiancai only had a pile of draft paper in front of him and could not see any questions at all.

"I'm thinking of a physics test question, would you like to try it?"

Zhao Xiancai tried to drag Cheng Zhijun into the water.

"Physics test questions? Where are they?"

Cheng Zhijun looked at Zhao Xiancai's desk again, but still didn't see any physics test questions.

"I saw this question elsewhere and kept it in my mind.

It goes like this, say a rigid rod AB, CD with uniform mass distribution is placed like this..."

As Zhao Xiancai spoke, he drew a simple diagram on the draft paper and wrote down the general content of the topic.

"This point A is in contact with the horizontal ground. The static friction coefficient between it and the ground is uA, B, D..."

After finishing speaking, Zhao Xiancai ignored Cheng Zhijun and continued to think about this topic.

"What are you looking at?"

Not long after, Zhou Yizhi, who was in front of Cheng Zhijun, saw that one of his strong opponents for the first place in the class was staring blankly at a piece of draft paper. He also looked at the draft paper in front of Cheng Zhijun with some curiosity.

Soon, Zhou Yizhi also began to think hard about this physics problem.

"What are you two looking at? Go to the toilet."

Wang Yisong, the last member of the top three groups in the class, also ran over at this time. The three of them usually like to gather together after class.

"Come and see how to solve this problem."

Seeing Wang Yisong coming over, Zhou Yizhi told him the question they were thinking about.

Soon, the three of them were discussing Zhao Xiancai's physics problem on the way to the bathroom.

"Old Biao, where did you get this question from? Why is it so difficult?

Do you usually say that you play with your phone when you go home every night, but in fact you are secretly doing the questions?"

Wang Yisong asked Cheng Zhijun.

The title "Laobiao" was originally a dialect of the neighboring province. It is a term of endearment for fellow residents of the same province.

However, although Chengxian County belongs to Anhui Province, it is located at the junction of three provinces. It is normal to mix some dialects from the neighboring provinces when speaking.

"This is Zhao Xiancai's question. I saw that he had been frowning since class. Then I asked him about it after class, and then I started thinking about this question."

Cheng Zhijun explained angrily that Wang Yisong usually liked to say this kind of thing, and after the exam, his favorite thing to say was "I didn't do well in the exam this time."

"Zhao Xiancai? Damn it, when did he start doing this kind of questions? It seems like we have another competitor!"

Although Zhao Xiancai's grades in physics, chemistry and mathematics had improved a lot in the last weekend exam, Wang Yisong didn't take it too seriously at the time. After all, it wasn't a big exam.

Moreover, at that time, Zhao Xiancai only had high scores in mathematics and physics, average scores in chemistry, and average scores in biology.

Now that Cheng Zhijun said this, Wang Yisong really started to pay attention to Zhao Xiancai.

"He is indeed quite smart. I think he may be smarter than Cheng Zhijun. You are not sitting next to him, so you don't know his changes.

Cheng Zhijun and I have watched his progress, and I can tell you this, every time he asks us questions on the same subject, the level of difficulty is not the same, so you can tell me that the speed is not scary."

Zhou Yizhi on the side also said to Wang Yisong.

"Yes, so don't compete with me anymore. I think it's better for you to compete with him."

Cheng Zhijun said again.

"If it's true as you said, then one of the top three in our class in the next monthly exam will be pushed out by him, isn't it?"

Wang Yisong looked like he was facing a formidable enemy.

"That shouldn't be enough. After all, there are so many subjects in the first year of high school, not to mention politics, geography and history, which we don't need to learn in the second year of high school. It's just English and Chinese. He has to study for a while, right?

If you really want to catch up with us, I guess I will have to wait until the next monthly exam no matter what."

Zhou Yizhidao.

Cheng Zhijun thought about that question for about ten minutes. Unexpectedly, he gave up on it and started looking at the seventh question.

After a lunch break and self-study in the evening, he would use the system's tutoring function to learn the solution to this problem.

"Hiss... ha... It seems that I spoke too early. Why do you feel that the seventh question is more difficult than the sixth question?

I can still do the first question on the sixth question, but I don’t know where to start on the seventh question.”

Until the school bell rang, Zhao Xiancai still didn't take action on the seventh question.

By the time the exam started on Saturday, Zhao Xiancai had only solved the 30th question out of the 70 physics questions he had bought with 7 points.

Among the thirty questions, starting from the sixth question, there are a total of 18 questions taught to him by the system tutor. Among them, 7 questions he solved by himself were also solved by summarizing some experience and solution ideas of other questions.
Chapter completed!