Longitudinal wave: The propagation of disturbance in slinky with the sound propagation in the medium. These waves are called longitudinal wave.
- Why sound are longitudinal wave?
Longitudinal waves the individual particles of the medium move in a direction parallel to the direction of propagation of the disturbance. The particles do not move from one place to another but they simply oscillate back and forth about their position of rest. This is exactly how a sound wave propagates, hence sound waves are longitudinal waves.