Fly in a straight line unless an outside force changes its course because i tried it once in a baseball game that my mommy rekt me in.
1. The amount of energy carried by the wave is related to the Amplitude of the wave.
2. A mechanical wave requires an initial energy input, Once this initial energy is added the wave travels through the medium until all it's energy is transferred.
The momentum of both the identical balls would eventually be transferred to one another when it comes to a point wherein they will collide. In addition, the phenomenon is called an elastic collision wherein both the momentum and energy of the system would considered to be conserved.
