What makes a wave mechanical
The wave on the slinky needs the slinky: without a material to travel through, there is no wave. A wave like that is a mechanical wave.
Mechanical wave
A wave that needs a material medium in order to travel is called a mechanical wave.
Examples
Water waves
Waves on the surface of water travel through the water.
Sound in air
Sound waves set up in air travel through the air.
A plucked guitar string
Plucking a guitar string sets up waves that travel along the string.
A slinky
The wave in Activity 4.1 travels along the coils of the slinky.
Two kinds, by direction
For a mechanical wave to move, the particles of the medium have to take part. Comparing the direction the particles move with the direction the wave travels splits mechanical waves into two kinds:
- Transverse waves
- Longitudinal waves