The teacher who taught undergraduate students at Yan University’s Mathematics College said to Shen Qi, why are you still here to teach?

Princeton has no horoscope, and Shen Qi's current identity is a bit awkward. He got his undergraduate degree in mathematics, but he couldn't immediately go to graduate school.

Life seems to lack a little passion.

To be fair, purely theoretical academic research is a boring thing, and it will not stop until death after years of boredom.

Shen Qi also wants to know the answer to how to seek some stimulation and fresh vitality in long-term theoretical research.

Shen Qi needs to take the initiative to seek passion in the dullness.

"Li Zhenqiang!" Suddenly, a professor on the podium roared and scolded him sternly: "What's wrong with you, a student? You're going to sleep for a long time in my big stuff class?"

Li Zhenqiang suddenly woke up with sleepy eyes: "I'm sorry, Teacher Sun, I was wrong!"

The old professor's face turned dark: "My surname is Ren, not Sun! The surname of Sun is to teach you the higher generation!"

After the senior high school class, a freshman in the mathematics department took college physics class in the same classroom, and the teacher was called Ren Buqi.

Professor Ren is about to retire, but his temper is very hot: "I can't even remember the last name of the teacher. Li Zhenqiang, your usual grade is 0 points!"

Li Zhenqiang's name is very domineering, but his personality is not strong, so he admits to his mercy.

The course in university physics is one of the compulsory courses in the mathematics department. You have me in mathematics and physics and you in me. It is difficult to draw a clear line completely. Love and kill each other is the norm.

Ren Buqi is a professor in the School of Physics, who teaches university physics courses for non-physics students.

Professors from the School of Mathematics also teach advanced mathematics classes for non-mathematics students.

"The final exam will be next month. Your math students are the worst class I have ever taught!" Ren Buqi was furious. Yan University School of Physics is very powerful. The style of professors in this college is completely different from that of the math school.

Shen Qi is very heartbroken. Professor Ren, you are too erratic. The average scores of our mathematics students in this class will definitely beat your physics department. As for our physics department, we have a quarter of the advanced mathematics department. Don’t ask me how I know, I have an informant.

"And you, Shen Qi." Ren Buqi scolded Li Zhenqiang and continued to scold Shen Qi, "As the class monitor, your attendance rate of your big material class is less than 50%. If you are a class monitor, just withdraw it." The teachers of the School of Mathematics didn't care much about Shen Qi, but the teachers of the School of Mathematics were very concerned about him.

"I really didn't play an exemplary role." Shen Qi said sorry. He was busy writing math papers and conducting degree defense this semester, and he really didn't pay much attention to physics.

Now that the bachelor's degree certificate in mathematics has been obtained, Shen Qi has formulated a plan to make great efforts to guide physics and seek breakthroughs in the branch of mathematics physics.

"There are more than 30 people in your mathematics department, and the number of attendees in this class is 15." Professor Ren's eyes were murderous, "Shen Qi, what do you think you should do."

"I'll call them back to class?" Shen Qi asked tentatively.

"No need." Ren Buqi said coldly.

No need, just three simple words, just ten strokes.

The students here understand the meaning.

"Okay, don't delay everyone's study time, continue to class." Ren Buqi paced back and forth on the podium, as if thinking.

After standing still, Ren Buqi compiled a question: "Take away the tables, chairs, podiums and all other items in this classroom, leaving only me and you, and ask what the total quality of us people is the ratio to the air quality in the classroom? Just estimate it, a must-have question."

Estimation is a method commonly used in physics. Generally speaking, the estimation results are not required to be very accurate, and there is only a small difference in order of magnitude.

There are often more than one method of estimation. It is simple and interesting to master. If you can't turn your mind, you will be at a loss.

The estimation question currently compiled by Professor Ren did not give any specific data, and asked what the ratio of human mass to air mass in the classroom is.

"It's interesting." Shen Qi wrote papers every day. He was irritated when he wrote too much of the paper. Occasionally, he would also adjust his physical and mental health.

Shen Qi quickly scanned the classroom. There were 16 humans, including one teacher, one student, one woman, and one man.

The height of the classroom is about twice the height of the human body. From the number of vertical rows of tables and chairs in the classroom, it can be estimated that the width of the classroom is about 10 times the width of the human body.

From the number of horizontal rows of seats in the classroom, including the additional rows converted from the podium area, it can be estimated that the length of the classroom is about 45 times the thickness of the human body.

Then, the space volume of the classroom is about 900 times that of a person.

Theoretically, this small classroom can be stuffed with 900 people in at the same time, and piled up as building blocks.

Take 16 to 900 to obtain the estimated value of the ratio of human volume to air volume in the classroom.

The volume ratio is estimated, and to obtain the mass ratio, a set of density data is also needed.

So the question is, what value is appropriate for the density of the human body?

The ability of humans to swim in water means that the density of the human body is similar to that of the water.

The molar mass of water is 18, and the average molar mass of air can be approximately 30.

Considering that water molecules are closely discharged, the spacing between air molecules is about dozens of times the size of air molecules.

Shen Qi finally estimated a value, 10.

It can be approximately believed that the total mass of 16 people in the classroom is 10 times that of the air quality in the classroom.

This estimate surprised Shen Qi a little. Is it that humans are too light or the air is too heavy?

The above observations were calculated in Shen Qi's brain and took about 15 seconds.

"How many?" Shen Qi asked Ou Ye beside him.

"10." Ou Ye also relies on mental calculation to obtain the estimated value.

That should be true. Shen Qi said to Ou Ye: "You will answer Professor Ren's question."

Ou Ye raised his hand.

Professor Ren: "Ou Ye, you estimate it, so fast? How much?"

Ou Ye: “10.”

Bang!

Ren Buqi snapped his fingers: "Ou Ye is quick-thinking and has an attendance rate of nearly 100%. You should all learn like her. That's right, the answer is 10. The quality of everyone in this classroom is approximately equal to 10 times the air quality. We only need to estimate the approximation of the order of magnitude, without having to worry about the accuracy. This is different from the higher generations of learning and the number scores. Physics is profound, comprehensive, flexible and changeable, and full of fun. Have you felt the fun of learning physics?"

Shen Qi found that physics teachers seemed to like to snap their fingers. This is the case with his high school football team, and the university physics teachers are still the case.

During the break, Professor Ren asked Shen Qi to speak separately: "I know you have obtained a bachelor's degree certificate. You may not come to listen to my big class, but should you urge other students to attend class?"

"I was not supervising effectively. Physics is of great significance to students in the mathematics department. I will let them teach and improve the attendance rate of the whole class." Shen Qi said.

"I heard that you won the gold medal in Cpho when you were in high school?" Ren Buqi asked.

Shen Qi nodded: "I have taken it. My teacher from the high school football team is a PhD in astrophysics from Yan University School of Physics."

"Oh, what's the name?"

"Teacher Mu Rongmu."

"It turned out to be Xiao Mu, my student." Ren Buqi said calmly, and a sense of a famous teacher arose.

Shen Qi's body trembled. I am Teacher Mu's student. Teacher Mu is Professor Ren's student. So by word ranking, Professor Ren is my ancestor!
Chapter completed!