longitudinal wave from wikipedia.com |
at frequencies within the range of hearing and
at a level that is strong enough to be heard.
at a level that is strong enough to be heard.
Sound waves are frequently, but not always, longitudinal.
The animation shows how the disturbance is transmitted for a longitudinal wave.
The direction of the deformation (from left to right across the page in the animation) for a longitudinal wave is the same as the direction in whch the wave travels.
The image below shows how the sound waves originating from a vibrating string are transmitted due to compressions and rarefactions of the air surrounding the string. The black dots represent the molecules in air.
The disturbance causes the air molecules to move back and forth about an equilibrium position. in the medium.
Restoring forces then return the medium to its equilibrium (resting) position.
The periodic (regular) deformation and restoration of the medium results in a transfer of energy from one point in the medium to another, but over time there is no net displacement of the particles of the medium.