A wave it is, for physics, a periodic movement which can spread in a vacuum or in a physical environment. Longitudinal , meanwhile, is what is located or developed in the direction or sense of length .
The propagation of a wave in a medium is linked to the vibration that generates in the particles of said means, medium . When the direction of propagation of the wave is equal to the direction in which the vibration of the particles of the medium is generated , the wave in question is qualified as longitudinal .
Is called longitudinal wave therefore to that which, in the particles of the medium, produces an oscillation movement that is parallel to the direction in which the wave itself propagates . Longitudinal waves differ from transverse waves , whose direction of propagation results perpendicular with respect to the direction in which the particles of the medium vibrate.
The sound waves , for example, are longitudinal waves. From the focus generated by the sound , wave fronts are moving away from the origin, causing a disturbance in the molecules of the medium in the same direction of propagation.
It is important to note that the sound wave causes a modification of the Pressure Sinusoidal in the air. The passage of sound is accompanied by a movement back and forth of the air in the direction of propagation of this longitudinal wave.
The disturbance produced in the middle by a longitudinal wave, in short, is parallel to the address in which the wave propagates. These longitudinal waves can propagate in gaseous, liquid or solid media.