Why can’t you jump, you can’t jump?
If someone asks you: Can you jump on your feet? Perhaps you could not answer immediately. So let’s try it out. You will notice that it is impossible to jump up if you do not bend your legs; almost completely, there is no place to deploy. What is that?
It turned out that in the general case, the motion of the object must obey certain objective laws, namely Newton’s law. Newton’s third law tells us that: When object A exerts a force on object B, of course, object B simultaneously impacts object A with a reaction, the magnitude of the force, and the reaction. Equal, opposite to each other, and in the same line. For example, when clapping, the right-hand acts on the left hand a force, the left hand simultaneously acts on the right hand again; put the book on the table, the book has a pressure on the table, and the same time produces support for the book. They are both force and reaction.
If we want to jump from the ground, we have to make the ground apply a force to us. But how can we make the ground impact us? That requires us to exert some force on the ground first. We bend our legs, lower, and then jump up to adjust the legs’ muscles, causing the muscles to contract and exert a force on the ground. Thus, the ground will simultaneously produce an upward reaction to us. Thanks to that jet, we jumped. The leg muscles apply to the ground, the greater the force, the opposing ground’s reaction, the bigger with us, so the higher you jump. If we do not bend our legs, our muscles will have no way of generating force against the ground, nor will the ground generate any reaction to us, so we cannot jump.
When a boat wants to leave the station, the person on the boat uses a bamboo pole to shore; the greater the resistance, the farther the boat leaves. That is also the law of force and reaction.