I just want to be a quiet scholar

Chapter 90 Who, who is it?
Z = 4
Z represents the nuclear charge of an element.

Which element in the periodic table has a nuclear charge of 4?

Hydrogen helium lithium beryllium boron, carbon nitrogen oxyfluorine neon...

It is clear that beryllium has a nuclear charge number of 4.

This problem explains, through a bunch of symbols, mathematical operations, and physical principles, a phenomenon in which Be2+ ions are trapped during the recombination process of a gas discharge.

After a series of derivation calculations, Shen Qi finally gave the answer: Z=4, which is the beryllium element.

From the macroscopic mirage to the microscopic ion capture, most phenomena in the world can be explained by mathematical and physical methods. This is the beauty of science and the power of science.

Of course, there are also paranormal phenomena that cannot be explained by human scientists, and these problems are left to non-humans above level 15 to solve.

Shen Qi completed the first two questions in an hour.

The first two questions do have a certain degree of difficulty.

This rematch exam paper is also naughty. The first two questions are difficult, but the big questions at the back are not too difficult.

第三题20分、第四题24分、第五题20分、第六题22分、第七题20分。

Shen Qi took another hour to complete the five calculation questions in the middle.

Two hours later, Shen Qi completed seven of the eight questions in the semi-final theory test.

The last calculation question has a score of 26 points, and the score is the highest in the whole paper.

"What the hell?" Shen Qi tried the questions three times in a row, "The big axis question is so simple? Give points? Or pretend to give points and die?"

The last question is:
"Suppose there are 4/5 nitrogen molecules and 1/5 oxygen molecules in the air."

"The temperature near the ground is 27°C and the pressure is 1atm."

"At a height of 10 km above the ground, there is a spherical artificial satellite with a cross-sectional area of ​​1 square meter, which orbits the earth at an initial velocity."

"Without atmospheric drag, the initial velocity of the satellite is just enough to allow it to orbit the Earth in a circular orbit."

"However, atmospheric drag is there."

"Try to find atmospheric resistance."

After Shen Qi reviewed the question three times, he tried it again three times.

Ha ha.

Scum.

Don't think that you are wearing a noble and gorgeous coat of 26 points, I will not dare to mess with you.

Shen Qi could finally be sure that the big axis sub-question with the highest score was just a paper tiger.

Putting a satellite is a physical phenomenon that combines mechanics and heat.

Because the atmosphere rises slowly, it can be regarded as the troposphere for static treatment, where there is a differential relationship between the pressure formed by atmospheric gravity and the decrease with height.

The stated ratio of nitrogen molecules to oxygen molecules comes in handy.

As the altitude increases, the atmosphere undergoes adiabatic decompression expansion, and the equation of temperature and pressure can be obtained.

With the help of mechanical knowledge, it is not difficult to estimate the initial velocity of satellite motion, which is close to the first cosmic velocity of 7.92km/s.

The collision between satellites and atmospheric molecules can be approximated as the elastic collision between the circular sections of the satellites perpendicular to the flight direction of atmospheric molecules.

Therefore, Shen Qi quickly calculated the result that the atmospheric resistance on the satellite is:
F=5.5×10^7N
The eight questions of the semi-final theory test involve optics, quantum theory, electricity, electromagnetism, mechanics, acoustics, preliminary astrophysics, and thermal science. The teacher who created the questions described the world of mortals through the test papers.

"The teacher who created the question considers himself a god." Shen Qi checked the test paper and then checked it again.

Although there were still 30 minutes, Shen Qi was not in a hurry to hand in the papers, check, and continue to check, and it took three hours to answer the questions.

"If I can't get 160 in the test, how can I face my ancestor Shen Gong?"

160 is the perfect score for the theory test paper for the rematch. Shen Qi did his best to respond to this test paper, and was determined to get 160.

After the game, Mu Rong gathered the 13 players who participated in the rematch to understand the situation.

"It's hard!" Bai Lingye shouted that my life was over.

"It's very difficult." Lin Xingyu looked solemn.

"There is a certain difficulty." Shen Qi said truthfully.

"Shen Qi, you didn't submit the papers ahead of time this time." Mu Rong felt that the situation was not optimistic.

"The first two questions are indeed a bit complicated." Shen Qi said.

"Hey, I didn't write the fill-in-the-blank question, so I can't deduce the trajectory equation. This question obviously touches the blind spot of my knowledge. The quantum theory of the second question is more abnormal, I wrote it blindly. The satellite question of the last question is atmospheric resistance. , I clearly have an impression, but I was stunned as soon as I took the test, I'm just a worthless salted fish." Bai Lingye said bitterly.

"Actually, what Teacher Mu said was that we didn't study well." Lin Xingyu looked for problems from himself.

"The 160-point theory test, I may not be able to take the 80-point test. Forget it, I don't have to take the test for the experimental questions. It's useless." Bai Lingye said dejectedly, advancing to the national finals and winning the national award , entered the physics experiment class of Yanda, and was finally left by Yanda... This is too difficult to do. Bai Lingye is also a primary school bully in their class. On the stage of the CPhO rematch, which is similar to the provincial test, he feels that he It's no different from a scumbag.

"Remember my classmates, never give up hope!" As a leader, Mu Rong must be optimistic, although she is a little pessimistic.

Nearly a thousand contestants from the whole province participated in the semi-finals. According to the practice of Southern Guangdong Province, no more than 20 people were finally selected to represent the province to participate in the national finals. Because the experimental questions have not yet been taken, Shen Qi does not dare to guarantee 100% that he can enter the national competition. After making a decision, he comforted the two juniors: "Lin Xingyu, Bai Lingye, you are only sophomores in high school, and you still have a chance next year. Teacher Mu is right, never give up hope, even this year, the one who doesn't give up hope is Salted fish, at least we can still fight on the experimental questions."

"Yeah!" Lin Xingyu nodded heavily, stubbornly letting himself hold on to a glimmer of hope and not let go.

"Okay, everyone has worked hard, go back and have a good rest, adjust your state, and disband." Mu Rong issued an order to dissolve, and everyone went back to their respective homes.

In the preliminary round, 94% of the players were eliminated, and the number of remaining players dropped sharply. The theoretical examination papers for the CPhO semi-finals are progressing rapidly.

One day later, the finalists will be able to self-check the results of the theory test for the finals on the China Physics Competition website.

Shen Qi used his mobile phone to check his scores, feeling a little uneasy.

Enter the test number and click "Search".

The mobile phone scoring system shows:

Name: Shen Qi

School: Nangang No. [-] Middle School

Exam No.: 10201XXX
CPhO rematch theory test score: 159
After seeing the score of 159, Shen Qi was shocked: "Who... who is embarrassing me? Why did I deduct one step point from me?"

A full score is a thing, if you don't taste it, you will become addicted once you taste it, just like smoking a crow pian.

The CPhO preliminary round and semi-finals won two "full points minus one point" in a row. No one can accept this cruel reality.

"So, even if I get a perfect score of 40 for the experimental questions, the total score in the semi-finals will be at most 199. I... I might not be able to make it to the national finals." Shen Qi felt the pressure.

"Brother, you are thinking of a master of learning, oh no, of thinking of a god of learning. You have a score of 99 in the exam of a master of learning, and you have a long-term perfect score of a god of learning. However, there are several gods of learning in the province, and a score of 159 in the theory test is very high! You Do you think everyone can get full marks in the test?" Lin Xingyu scored 130 points in the theory test, which he was quite satisfied with, already exceeding his expectations.

(End of this chapter)