Wang Yiyi pointed to the guide rail on the lectern and said, "Before I talk about today's content, I will give you an experiment. ”

The so-called test is very simple, Wang Yi picks up a steel ball on the far right of the guide rail, and then lets it roll on the guide rail, when it collides with other steel balls in contact with each other, the leftmost steel ball is naturally ejected and rolls to the left for a distance. Because the coefficient of friction between the guide rail and the steel ball is negligible, the rolling process can be considered to be free of unnecessary kinetic energy loss. When the ball stops, the distance traveled by the ball is roughly equal to the distance of the initial ball on the right. This is a very simple experiment of conservation of energy, but anyone who has studied in the afterlife should be familiar with it.

Of course, these students in the classroom are no strangers to this, they are all a new generation that has grown up in the education system established by Wang Yiyi. Wang Yi liked this feeling, with a familiar flavor for later generations, which made him no longer seem to be an outlier. The integration of the later life and the previous life has brought about the current Dashang Affiliated School, and only in such a place will Wang Yi's thoughts about the time before the crossing be less urgent, and the pain in his heart will be relieved a little.

Wang Yi's voice echoed in the classroom, but there was a person who seemed to be out of the way. Physics is a completely foreign world to Xu Shichang. He naturally understood the content of the test, Wang Yi didn't put any formulas, and the one qiē looked very simple. He didn't understand what Wang Yi's specific purpose was in this experiment, he always felt that it was a superfluous move, and the results of the experiment were not obvious! He can roughly guess the result without testing.

However, before he despised physics and was secretly proud in his heart, Wang began to lecture, and Xu Shichang was dumbfounded. The Book of Heaven is nothing more than that, what are the ghost talismans on the blackboard? But don't say it, Xu Shichang, a person who can gain fame, really doesn't have a fake memory. He was able to remember all the meanings of the letters that Wang Yi talked about in court, but the basic knowledge of physics and mathematics was too difficult for a layman. It's one thing to memorize and understand what is in class, it's another thing to actually apply the formulas he has learned to calculations and applications, which is really difficult for him.

Looking at the bright eyes of the students around him when they were listening attentively to the class, Xu Shichang suddenly felt a little ashamed of himself. Since joining the company, I don't know when I started, I lost the tireless study mind of the children in front of me, and my heart was full of calculations for fame and fortune. Every day is a miasma, living in a new barracks, it seems that I have a career, but when I dream back at midnight, I always feel an unprecedented emptiness. It was a blank idea of the future, as if I was stuck in a suffocating mud pond, unable to extricate myself.

"Whoever is not like this in the officialdom is not as pure as these children."

Xu Shichang sighed silently, he didn't look down on Western studies before, and at the beginning of today's class, Wang Yi's experiment also gave him a feeling of naivety to the point of ridiculousness. There is no need to do the test, he Xu Shichang can guess the result, everything is deserved, there is no doubt about it, isn't it?! However, when Wang Yi explained the principle behind the whole experiment, the profound truth contained in the numbers and formulas made Xu Shichang, a man in his thirties, begin to feel dizzy.

"The road is simple! Behind the simple phenomena that we have long been accustomed to, there is always a profound truth that is mystical and complex. No wonder Wang Yi's dislike for Confucianism is so deep, it turns out that we self-righteous scholars have lost the whole world. ”

Time passed quickly, and in the process of Xu Shichang's cranky thoughts, the whole class had come to an end. The students did a few practice problems according to some physics formulas, and then Wang Yi gave them homework. Seeing that there were still more than five minutes left, Wang Yi smiled at this time: "There are still a few minutes before the end of class, so I'll make you an interesting practical one." ”

There was originally a noisy class, but at this time, it quieted down, and Wang Yi successfully attracted the attention of the students.

"Students, I think you should know that the ultimate goal of learning is to apply what you have learned. Of course, some students will also question whether the things we talk about in class today are really useful in their future lives. Wang Yi smiled, looked at these students in the classroom, and said calmly: "It is likely to be useless, but it is also likely to be useful!" I don't have a definite answer here, the key is up to you, and the profession you will do in the future will determine the usefulness of this knowledge. There will always be countless choices in life, and in the same way, a person may have many jobs in his life. Just like me, who runs a company, I usually find time to give you lectures, go to the hospital to see patients, and sometimes go back to the research institute of Dashang to give simple guidance on certain projects. What are we learning today? ”

"Physics."

"That's right! But at the same time, it is also the key, the key that opens the way to your future life! Wang Yi turned the topic back to the experiment at this time and said: "Today, everyone has learned about conservation of energy, which is one of the most basic principles in the world, and will have a wide range of applications in thermodynamics in the future. However, the test I am going to show you now is actually an extension of the guide rail test at the beginning of the course. Here, I would like to ask you a question, what do I do to get this ball on my left hand faster speed? ”

The classroom fell silent as students pondered their questions. Xu Shichang was also attracted by Wang Yi's question, frowned, and gently touched the beard on his chin.

After some time, Wang Yixiao asked, "Does anyone have an answer?" ”

A boy said, "Sir, use your right hand more vigorously, and the ball on the left will naturally roll farther away." ”

This method was probably the easiest to think of, so that all the students felt a little stupid and burst into laughter. Wang Yi didn't care, and said: "It's a way, and it's very simple, but although your husband and I are talented, but the manpower will eventually be exhausted, so I can't reach the Cheng dù I want!" Does anyone else have another way? ”

The students began to talk about it, not to mention it, but they really came up with several methods.

The king nodded and said, "Everyone's methods are good. ”

"What is the gentleman's method?" The girl who recognized Wang Yi's identity before asked.

"Want to know?" This product was sold in a lawsuit.

The students nodded curiously.

"Well, everyone, look at it!" Wang Yi mysteriously blocked a section of the guide rail with a book, and then gently pushed out the steel ball in his right hand, and the scene that followed surprised the students. The ball on the far left is ejected, which is significantly farther away than the ball on the right.

"What's going on?" "Why?"

Wang Yi removed the book, picked up the cylindrical steel block placed on the guide rail, and a string of steel balls were all sucked up, and said, "This is a magnet." ”

The students suddenly realized, but before they could ask, Wang Yi said directly: "The principle is very simple, but I want to ask now, if this guide rail is replaced with a steel pipe, and then repeat the test just now." What do you think this thing looks like? ”

One of the boys was the first to react, saying, "Cannon!" ”