Chapter 489
"How heavy can you lift up?" Wang Yang asked Zhao Ji.
After thinking about it, Zhao Ji raised his finger. "It's no problem with one hundred pounds. If it's more, it's a problem, it's going to be hard."
"That's fine, Qilang, you can lead two people to get 300 kilograms of steel ingots, and then get a large scale." Wang Yang ordered Wu Qilang.
Zhao Ji looked at Wang Yang with a confused look on his face. He really didn't understand what the old driver wanted to do. He quickly stated loudly. "Three hundred kilograms? Sir, what are you doing? Even if you use the energy to feed your breasts, you can lift up to 150 kilograms of heavy objects. No matter how much you have, it's really not possible."
"Hehe, why are you in a hurry? Could it be that I can still press the 300 pounds on you? Then you will know the magical use of this pulley set. Now, please forgive me for keeping it confidential for the time being."
After a while, Wu Qilang and others came to Wang Yang's office with stinky sweat on their heads.
In addition, he also brought the big iron hook and scale that Wang Yang needed. Wang Yang first asked Wu Qilang to stand on the table, nailed the iron hook tightly on the sturdy beam, and then hung a large pulley on it, then brought a hemp rope and started to pass through the pulley...
Zhao Ji was confused, but the problem was that Wang Yang just didn't tell him, but just asked him to wait and see the results. Until all the pulleys were finished, a solid bamboo basket was hung on the bottom pulley hook for steel ingots.
Although the 300 kilograms of steel ingots are very heavy, their size is not very large. After the sturdy bamboo basket was filled with the 300 kilograms of steel ingots, there was even room for spare.
Wang Yang tilted his head towards Zhao Ji. "How about it, let's try it first. Is the bamboo basket weighing 300 kilograms?"
"Me?" Zhao Ji pointed to the tip of his nose and looked at Wang Yang with disbelief, his expression as if he had just broken a dog.
"Your Highness, I just asked you to try it, but I didn't say I had to pick it up." Wang Yang encouraged with a smile.
In the end, Zhao Ji had to bite his teeth and stepped forward, then stood in front of the bamboo basket and started to work hard. Well, Zhao Ji's little face turned red like a monkey's butt, but he couldn't lift the bamboo basket up.
"No, it's really not possible. Three hundred kilograms must weigh 300 kilograms, so there is absolutely no doubt about this." Zhao Ji, who seemed a little panting after trying several times, retreated and held the case and gasped for a while.
"Then your Highness, please try to pull the rope again to see if you can lift the 300-pound steel ingot." The smile on Wang Yang's face still seemed so mysterious.
"Still playing? No, no, I really can't lift it up sir." Zhao Ji almost rolled his eyes and fainted.
"Your Highness, you can do it, just like me, one step, one step, one step, one step... Look, how simple and easy, just go up and down." Wang Yang continued to maintain a mysterious smile, and then began to pull the rope.
Then, Zhao Ji saw that Wang Yang was just pulling the rope passing through the pulley set with one hand. The bamboo basket containing 300 kilograms of steel ingots was so light that it was up and down as if nothing had happened.
Zhao Ji's eyes were glaring into the Big Wild Goose Pagoda in Chang'an. "You, can you make tricks?"
"You try it and you will know if it's a trick. Come on, Your Highness, you can do it." Wang Yang waved to Zhao Ji.
This time, Zhao Ji was not polite and rushed to Wang Yang with great strides, took the rope, pulled it up, and then saw the basket that almost made him hold out, but he couldn't lift the slightest bamboo basket, as if it had only weighed dozens of kilograms.
With a little force, you can see the 300-pound bamboo basket gradually left the ground and was lifted up by himself. Zhao Ji let go of his hand in a confused look. With a muffled sound, the bamboo basket hit the floor hard, which scared the three people in the room.
Zhao Ji was embarrassed and quickly apologized repeatedly, and then went over without believing in the evil spirit and carried the bamboo basket again, which was still unshakable. But when he pulled the rope again, the bamboo basket rose from the ground again.
"This, isn't this a magic trick but a magic trick?" Zhao Ji felt that he was almost unable to control himself. Damn, could he actually do magic tricks?
"Wrong, this is neither a trick nor a demon, but a physics." Wang Yang shook his head slowly, raised his index finger with a serious expression and said incredibly serious manner.
"What the hell is physics?" Zhao Ji looked at Wang Yang with a confused face, and felt more and more that the idol he admired seemed to be flashing behind him.
"Physics is the discipline that studies the most general laws of matter movement and the basic structure of matter. Its theoretical structure fully uses mathematics as its working language and uses experiments as the only criterion for testing the correctness of theory. It is the most sophisticated natural science discipline today." Wang Yang explained very well.
Just like when I first came into junior high school, the old teacher with gray hair was as rigorous as ever. "And this pulley set is a practical experience in physics."
"The pulley set is a simple machinery assembled by multiple moving pulleys and fixed pulleys. It can save labor and change the direction of force. The amount of effort saved by the pulley set is determined by the number of rope strands, and its mechanical efficiency is determined by the gravity of the object being pulled, the gravity of the moving pulley and the friction of the moving pulley."
Seeing that Zhao Ji was still confused, Wang Yang couldn't help but sigh softly, then walked to the side, took out a book, walked to Zhao Ji and handed it to him.
"The Mo Jing? Does this thing have anything to do with this physics?"
"You can take a look at it yourself. There are records about pulleys in the "Mo Jing", and Wang also obtained a source of inspiration from it and copied the pulleys that Mo Zi and the others used at that time."
In 388 BC, there are records of pulleys in the book "Mo Sutra" written by Mo Modi (known as Mozi) and his disciples.
It is also recorded in detail that the pulley with a fixed central axis is called a fixed pulley, which is a deformed equal arm lever that does not save effort but can change the direction of force.
The pulley that moves with the central axis and the heavy object is called a moving pulley. It is a deformed unequal arm lever that can save half of the force, but does not change the direction of the force.
In practice, a certain number of moving pulleys and fixed pulleys are often combined into various forms of pulley sets. The pulley sets save both effort and can change the direction of force.
Chapter completed!