# Wave Motion - Mission WM1 Detailed Help

 Which one of the following best describes the means by which a wave transports its energy along a slinky from coil A to coil Z?
 Nature of a Wave: A wave results from a periodic and repeating disturbance of a medium at a given location; energy is transported from that location through the medium by means of particle-to-particle interaction. While energy moves through the medium, the actual particles of the medium simply undergo a back-and-forth vibration about a fixed position.
 Suppose that you and a friend stretched out a slinky and held it at opposite ends. Then suppose that you begin to introduce waves into the slinky by shaking it up and down at one end. The disturbance at your end (coil A) would be transported to your friend's end (coil Z) through a coil-to-coil interaction. Quite clearly coil A would remain in your hand; it would not move down to your friend's end since you are holding onto it. Yet the disturbance moves to your friend's end because all the coils are connected. Coil A pushes or pulls on coil B; coil B pushes or pulls on coil C; coil C pushes or pulls on ... and so on.
 A common misconception (wrong idea) regarding waves is that a wave involves the movement of matter from the source to other parts of a medium. But don't be fooled! Waves involve the transport of energy, not the transport of matter. In a slinky wave, the coil on one end stays on that end; clearly it doesn't move to the other end. It is the disturbance at one end that moves to the other end by means of particle-to-particle interaction.