I just want to be a quiet scholar

Chapter 97

Solid physics is also related to chemistry, with some incredible properties of physical chemistry.

Materialization is so annoying, those who study physics are afraid of it, and those who study chemistry are also afraid of it.

In fact, Shen Qi is also a little terrified. This thing turns things into things, but it doesn't change things. Killing people doesn't pay for life, it just wants you to die.

For this question, the sum of the interaction energies Ep between ions in the NaCl crystal is given.

When r deviates from r0, Ep deviates from Ep0, and the deviation is set as U.

Then use x to represent the relative offset. To obtain the power series relationship between U and x, a Taylor expansion must be made, that is, the Taylor expansion of Ep at r0 is used.

It's really torturous. To do a physics problem, you have to develop Taylor's expansion. Fortunately, Taylor's expansion is very simple...Shen Qi began to answer the questions on the test paper.

The power series expression of U(x) is:

U(x)=A0+A1x+A2x^2+A3x^3+……

……

From adiabatic compression, it can be known that:
1/κ=-V(dp/dV)∣r=r0
......d^2Ep/dV^2=d/dV(dEp/dr*dr/dV)=...

最终得：m=9.4；α=1.77；am=2.53×10^-109J*m^9.4
I don't know if it's right or not, it can only be like this, time is short, and there are five questions to follow.Shen Qi hurriedly entered the answer to the following question.

The fourth question, at first glance, was sparse and ordinary, but Shen Qi thought about it carefully.

"A certain amount of ether is encapsulated in a glass tube, some in liquid state and the other in gaseous state."

"There are no other impurities in the tube. If the volume in the tube is exactly the critical volume of these ethers, then when slowly heated to the critical temperature, the liquid level disappears because there is no longer a difference between the gas and liquid phases..."

Although the first three questions took a lot of time, on the fourth question, Shen Qi carefully reviewed the questions again.

When the trial question arrived here, Shen Qi had an ominous premonition, and his spine was whizzing with chills.

Another liquid, another gas, and another critical...

This shows what?
What does this herald?
Van der Waals gas!

There is no doubt that when it comes to Fan's gas, it must be a pure materialization problem.

Afraid of what to come.

is it?

It's it!

It shouldn't come.

But it has come.

It still came after all.

Silence, a moment of silence.

Shen Qi must do it in the shortest time possible.

solve a problem.

in glass tube.

The ratio of gas and liquid phase.

Exactly how much?
Ether, colorless and transparent.

But it is the life-threatening liquid in the materialized rivers and lakes.

Deadly, liquid.

Murder is invisible.

Where there is van der Waals, there are rivers and lakes.

But the most dangerous is not the liquid.

Instead.

Gas and liquid coexist.

Bg and B1.

Finally, Shen Qi started writing:

Taking 1 mol of ether, with the change of temperature, the total volume is Vk, and the mole fractions of the gas phase and liquid phase are α(T) and β(T), respectively.

αVg+βV1=Vk
When the temperature is T, the saturated vapor pressure is p0, and by the equal-area method, we get:

∫ Upper Vg lower V1pdv=p0 (Vg-V1)

Substitute the points to get:
RTlnVg-b/V1-b-a(1/V1-1/Vg)=p0（Vg-V1）

……

By Fan's equation:
……

ΨFan's ΦΨ equation*Baobu 卍

……

Get:

Liquid B1=44.1%
Gas phase Bg=55.9%
In the end, Shen Qi gave his answer, that is, the proportion of liquid B1 and gas phase Bg.

Completed the first four questions, time spent 2 hours.

With the last four questions left, Shen Qi only had one hour to answer.

It's not that he doesn't work hard, this national final exam paper is really difficult.

After completing questions 5, 6, and 7, Shen Qi had only 10 minutes left.

At this moment, the contestant in front of Shen Qi packed up the stationery and raised his hand.

Shen Qi is very familiar with this kind of behavior. He used to do this often and submit papers in advance.

The invigilator walked over to the classmate in front of Shen Qi and asked softly, "Hand in?"

"Yes." The contestant nodded. He was from Suzhou-Hangzhou No. [-] Middle School, a strong school in Zhejiang Province.

The player from Suzhou-Hangzhou No. [-] Middle School was sitting in front of Shen Qi, and Shen Qi couldn't ignore it if he wanted to.

Whether it is a number competition or a physical competition, teachers and students who engage in subject competitions have heard of the name of Suzhou-Hangzhou No. [-] Middle School.

It is also a No. [-] middle school. Shen Qi's Nangang No. [-] Middle School is incomparable to other people's Suzhou-Hangzhou No. [-] Middle School. They operate as a group, and there are sub-rudders everywhere.

"Do you like it or not, I'm tired of playing this way of playing." Shen Qi watched the contestants from Suhang No. [-] Middle School leave and began to review the last question.

The last question is not easy, it will take a few minutes to read it carefully.

"In a particle collision experiment, a low-velocity k-meson was observed to interact with a resting proton p to generate a π+ meson and an unknown x-particle."

"The magnitude of the magnetic induction of the known magnetic field B is B=1.70Wb/m^2, and the radius of curvature of the π+ meson track is measured as R1=34.0cm."

"1. Try to determine the radius of curvature R2 of the x-particle track."

"2. Please see the table below:

The headers are: particle name, symbol, -static mass/MeV+, charge (e)

The specific information for each row is:

Positron, electron; e+, e-; 0.511; ±1
muon; μ+, μ-; 105.7; ±1
pion; π+, π-; 139.6; ±1
neutron;n;939.6;0
Λ particle; Λ^0; 1115.4; 0
Negative Σ particles; Σ-; 1197.2; -1
Neutral Ξ particles; Ξ^0; 1314.3; 0
......"

There are a dozen lines in the particle list.

The second question is: "What kind of particle is x?"

10 minutes, judging the question plus answering a total of 10 minutes, Shen Qi only had 10 minutes left.

This needs to be replaced by ordinary people, and it is estimated that the answer to the last question has to be given up.

But Shen Qi didn't give up. After carefully reviewing the questions, he still had 7 minutes left.

This is a topic of modern physics. The idea of ​​solving the problem should be... What kind of ideas do you need? The situation is critical at the moment of fire.

Shen Qi picked up the pen without hesitation.

Taking into account the Lorentz force, the magnitude and mass of the two particles remain unchanged.

Newton's second law in the form of relativity:
F=d/dt (mv)

……

π+ meson and x particle make circular motion under the action of Lorentz force, and the rotation radius is:
R=mv/eB
……

因m1v1=m2v2，且两粒子的电量绝对值相同，故粒子圆形径迹的半径R2与π+介子圆形径迹的半径R1相同。

Get R2=R1=34.0cm
Shen Qi took 3 minutes to get the answer to the first question. The radius of curvature R2 of the x-particle track is the same as the R1 of the π+ meson, both 34.0cm.

My problem-solving speed is no longer there, it is faster than the speed of particle movement... Shen Qi completed the first question with the speed of light.

There is no way, everyone is forced out, and in the face of adversity, a level 15 combat power may erupt.

God, why is R2 equal to R1, I don't believe this answer myself... Shen Qi has to believe it even if he doesn't believe it, there are more than 3 minutes left, he must complete the second question immediately, and he doesn't have time to check the correctness of the first question.

The second question asked Shen Qi to determine what kind of particle x was.

Based on the radius of curvature of the x particle obtained from the first question, R2=R1=34.0cm, Shen Qi needed to perform some calculations to determine which particle x was.

If the answer to the first question is wrong, the second question must also be wrong.

There is no turning back, there is no time.

Even if the first question is wrong, you have to bite the bullet and make a mistake!
This is Shen Xueba's last stubbornness.

Shen Qi once again showed his light-like hand speed and powerful mathematical operation ability, and he calculated directly on the paper:
v1=eBR1c/根号m10^2c^2+e^2B^2R1^2=1.6×10^-19×1.7×0.34×……m/s
……

Although the time is tight, Shen Qi still deduces and calculates according to the steps he thinks are rigorous and correct. The formulas that should be written must be written completely, and the key steps that need to be explained in words must be written in a few words, such as "substitute, get", This is the basic quality that a scholar should have.

Substitute in, get: m20c^2=1196MeV
1196MeV...Shen Qi compared the particle information list on the paper, so x is a Σ-particle?

Jingle Bell!
At this moment, the bell rang.

Shen Qi pressed the bell and wrote the final answer on the scroll: x is a Σ-particle.

It is really the speed of life and death, the speed of life and death of the competition version.

Although the examination papers were handed in hastily and there was no time for inspection, not even a one-minute inspection, as a top student, he should walk out of the examination room calmly and gracefully. This is also the basic quality that a top student needs to possess.

Shen Qi walked out of the examination room calmly and gracefully, ah, there was a light rain in the sky, what an unusual day.

"It is very difficult to get full marks on the theoretical questions of the national finals. From the preliminary round to the semi-finals, from the semi-finals to the finals, I participated in three physical competition theory tests. The worst case may be that I can't get full marks in one theory test. "Shen Qi was walking in the light rain, pattering.

"Shen Qi!" Suddenly a voice came from behind, and Mu Rong chased after him with an umbrella in her hand.

Mu Rong held an umbrella, the bottom of the umbrella just accommodated the two teachers and students: "How was the test?"

"Let me hold the umbrella." Shen Qi took the umbrella. He was more than ten centimeters taller than Mu Rong, who was struggling to hold the umbrella.

"It looks like you are very calm." Mu Rong observed Shen Qi's expression.

Shen Qi whispered: "Bamboo sticks and mans shoes are lighter than horses, who is afraid."

"Yi Minyanyu is a lifetime." Mu Rong immediately took the next sentence, and then asked cautiously: "Shen Xueba, can you get full marks in the exam after being resurrected with full blood?"

(End of this chapter)