Waves can be described as oscillations or vibrations about a rest position. For example:
Longitudinal waves show areas of compression and rarefaction:
In the diagram, the compression moved from left to right and energy is transferred from left to right.
The movement of the coils of the slinky and the energy are parallel.
However, none of the particles are transported along a longitudinal wave.
Instead, they move backwards and forwards as the wave is transmitted through the medium.
Examples of longitudinal waves include:
One way of remembering examples of longitudinal waves is to emphasise the O in lOngitudinal and sOund and ultrasOund.