The wave speed of simple harmonic vibration! !

Wave velocity is the speed of wave propagation, not the speed of particle motion.

It is the direction of wave propagation, and the topic is the speed in the X axis direction.

Briefly talk about the meaning of wave velocity. The so-called wave velocity means that when t=0, the particle at x=0 starts to vibrate. Affected by the vibration of x=0, the nearby particles also start to vibrate. At t=t0, the particles at x=x0 also start to vibrate. Suppose the wave propagates from x=0 to x=x0 within t0. So the wave velocity at this time =t0/x0. Obviously, this wave velocity is not directly related to the vibration velocity and motion trajectory of the particle itself. It is directly related to the ability of medium to transmit vibration.

An obvious example is that if there is no medium in a vacuum, no matter how violent the vibration of particles is, it can't propagate vibration, no matter how mechanical waves are formed.

It has nothing to do with ballistics. Is the distance of the x axis. Nor is it the distance of moving particles in the x-axis direction. It refers to the X-axis direction. How far away the particles are, they begin to vibrate.

Otherwise, let me make an analogy to illustrate. Just like a group of people. First, people stand together. Then the person standing at the end got the order and began to jump. So I met the person in front, and the person in front knew to jump. I met the person in front of me again. First of all, everyone just dances in the same place. But after a while, everyone knew they were going to jump. The so-called "wave speed" is similar to how long it takes, and the first person knows that it is time to jump. This time, the last person, of course, stayed behind and danced in situ. The speed at which this "jump" command spreads has nothing to do with the speed at which everyone jumps.

The last question is to know the wave velocity and ask how to calculate the distance that a certain point passes in a few seconds.

It is impossible to calculate the distance of a certain point only by knowing the wave velocity. Because we have to use wave velocity and wavelength to calculate frequency. Knowing the frequency can tell how many times the particle vibrates in a few seconds. Then you must know the amplitude to calculate the distance. It is impossible to calculate the distance of particles only by knowing the wave velocity. But you can calculate how far the wave has traveled in a few seconds.