Mr.Hanson makes a rope by stringing dozens of tennis balls together. He ties one end of the rope to a tree and makes waves by rapidly moving his end up and down.
As the wave moves from left to right, each tennis ball
A) moves up and down
B) remains motionless
C) moves from right to left
D) moves from left to right

Respuesta :

The Answer Is A: Moves Up And Down

If the source is up and down, so are the waves. I had the same question on Study Island :)