The several staff members who came to Xinxueguan as teaching assistants originally had a headache, because most of the students in Xinxueguan did not have a good reputation.
In the past, I was a messy person in the academy, and I was worried that after coming to the new academy, it would be more difficult to manage after leaving Chang'an.
But what surprised them was that on the first day, everyone acted as if they were completely different people.
Today, the martial arts department led by Lao Cui and Lao Du and several instructors began to conduct physical tests on these martial arts members. They wanted to test the physical limits of each of them and which areas they were more specialized in.
As for science, Tang Ping teaches in person.
"We have a lesson today that I call a physics lesson!"
"The so-called physics can be understood as the principle of how everything in the world operates!"
At the front of the classroom, the craftsmen who built the new school had already placed a large wooden board at the front according to Tang Ping's request, and then painted it with black paint.
Tang Ping wrote the word "physics" in big letters on the blackboard with chalk.
Now these students also know that they cannot whisper to each other casually in class, so although they have endless questions in their hearts, they can only hold them in their hearts.
Then Tang Ping wrote sixteen more characters on the blackboard: "The mystery of the universe, the microness of particles, the movement of all things, and the complexity of daily use."
Then he circled the next two points: "For you now, we can start with the last two points!"
After saying that, he took out the things he had prepared long ago, which were a small bracket and a wooden board.
First, place the middle of the board on the bracket. After the board is balanced, put a copper coin on it. Then obviously, the end of the board where the copper coin is placed begins to sink.
"Who knows what this is?" Tang Ping asked, looking at the students below.
"Isn't it just because the copper coins have weight?" Li Tai, sitting in the first row, said with some disdain.
I originally thought that this science subject would talk about something. The sixteen characters written by Tang Ping just now were also very mysterious and mysterious, but it turned out that it really started to talk about such simple things.
Not to mention now, he almost understood this when he was five years old.
"OK, then what if I put a copper coin on the other end?" Tang Ping looked at Li Tai and asked.
"Of course the board will balance again!"
"Oh, really?" Tang Ping smiled and took out another copper plate, but unlike the previous one which was placed on the edge of the board, this time although he placed the copper plate on the other end, it was closer to the middle one. stand.
Therefore, the board did not regain its balance as Li Tai said, but still tilted towards the end where the first copper plate was placed, but the amplitude was not as large as it started.
"You... you have to put the copper plates on both ends!" Li Tai said anxiously.
"Okay!" Tang Ping put the second copper plate to the side as he was told, and this time the board finally regained its balance.
"Then please ask Li Tai, what is the principle of this?"
Li Tai: "..."
Yes, why? If a copper plate of the same weight is placed at different positions on the board, the board will have different tilt angles?
Before he could figure it out, Tang Ping took out another copper plate and asked, "Then if I put two copper plates on one side and only one on the other, what will happen to the board?"
Li Tai replied without thinking: "Of course it leans towards the side where the two coins were placed!"
"Oh, really?" Still the same words, the same smile.
Then Tang Ping adjusted the position of the wooden board on the bracket, and then placed the three copper plates on both sides.
This time the board did not tilt toward the side where the two copper plates were placed as Li Tai said, but remained horizontal.
Although Li Tai could see that the wooden board was the same as before, not placed in the middle on the bracket, he couldn't figure out the principle.
This is a very simple leverage principle. Ancient people have actually used the leverage principle for a long time, but they did not have a complete theory to explain this phenomenon.
During the Warring States Period, although the concept of applying leverage was mentioned in Mozi's book "Mozi", there was no detailed explanation as to why such a phenomenon occurred.
It only took Tang Ping a few minutes to make the extremely proud Li Tai start to doubt his life.
But it wasn't over yet. He took out two more iron balls. The difference in size between the two iron balls was very obvious, and then asked his classic question.
"If two iron balls, one big and one small, fall from a height at the same time, who will hit the ground first?"
"I know, we landed at the same time!" Du He, who was sitting in the middle, shouted loudly. After shouting, he looked proudly at the students around him.
"Landing to the ground at the same time?" Li Tai was confused, and then whispered: "Shouldn't the bigger one land first?"
Although his voice was very low, Tang Ping still heard him as he was sitting in the front row.
This time Tang Ping did not do the experiment first, but started drawing on the blackboard.
There is a small circle on the left, a large circle on the right, and a small circle connected to a large circle in the middle.
"Li Tai, look, this is a small iron ball, this is a big iron ball, this is a small iron ball and a big iron ball connected together, who do you think will hit the ground first?"
Li Tai was about to say the ones that were connected together, because the ones that were connected together were obviously the heaviest.
But he paused before the words came out, because if the small one falls slower, then the small ball and the big ball are connected together, shouldn't it pull the big ball and slow down the big ball?
This creates a paradox!
Could it be that Du He, that coward, was right? Did the two balls really hit the ground at the same time?
Li Tai began to doubt life for the second time.
But it wasn't over yet. Tang Ping took out another feather from under the stage and asked, "What if the feather and the iron ball fall at the same time?"
"They still landed at the same time!" Du He shouted from behind, and then the classroom burst into laughter.
Because others may still have doubts, but who hasn’t seen this scene of feathers slowly falling from a high place? How fast did the iron ball fall? When the iron ball hits the ground, the feathers may still be floating.
Du He also realized at this time, yes, the feathers can fly, so he blushed and didn't know what to say.
"You think Du He said something wrong, don't you?"
"yes!"
"Of course. How slow are the feathers floating down?"
"Exactly, how could the feather and the iron ball hit the ground at the same time?"
Tang Ping smiled and took out another thing from the audience. This was a teaching aid he specially purchased online. It was a long vacuumed glass tube with a feather inside.
"Look, there's a feather in it, right?"
Although the long glass tube that Tang Ping took out looked very shocking in this era, at this time everyone's attention was attracted by the feather inside.
Tang Ping didn't say much and stood up the long glass tube, which was almost two meters long.
Then the students below were surprised to find that the feather inside was no longer floating slowly when it fell, but fell at an extremely fast speed.
The speed was almost the same as when they saw other objects falling.
Li Tai began to doubt life for the third time.
