Define longitudinal and transverse wave.

Transverse Wave:

1. In a transverse wave, the particles are displaced perpendicular to the direction the wave travels.
2. Examples of transverse waves include vibrations on a string and ripples on the surface of the water.
3. We can make a horizontal transverse wave by moving the slinky vertically up and down.

Longitudinal Wave:

1. In a longitudinal wave, the particles are displaced parallel to the direction the wave travels.
2. An example of longitudinal waves is compressions moving along a slinky.
3. We can make a horizontal longitudinal wave by pushing and pulling the slinky horizontally.