1. Section 7-2

2. The particles of the medium move up and down at right angles to the direction of the motion of the wave. Ex. Pull up and down on a rope tied to a doorknob, ocean waves.

3.  Crest – The high point of a transverse wave.  Trough – The low point of a transverse wave.

4. A wave in which the particles of the medium move back and forth in the direction of the wave motion. Ex. Clap of thunder.

5.  Compression – A clap of thunder pushes the particles of air close together. The compressed particles move forward in the direction of the wave motion.  Rarefaction – As the particles move forward, they leave behind a part of the wave where the particles are far apart. It also moves forward in the direction of the wave motion.