An example of a mechanical longitudinal wave, or a compressional wave, is a sound wave. Another example is primary waves of an earthquake. Both travel through their respective medium, either air and Earth, while the particles constituting these mediums move in the direction parallel to the wave.
A compression wave is a mechanical longitudinal wave. The longitudinal wave constitutes the movement of the compressed region of matter in one direction. The particles of which that matter consists, however, do not move along with the wave. They are displaced in the direction parallel to that in which the wave propagates.
To visualize a compressional wave in a nonwave example, picture a slinky toy. The compression of the spiral rings appears to be a wave traveling from one end of the slinky to another, while individual rings simply oscillate around their original points of rest.
- One example of a compressional wave is a sound wave - which travels through air, an elastic medium, with the help of pressure. The speed with which a sound wave travels through air depends on the characteristics of the air.
- Another example of a compressional wave is seismic P-waves, or primary waves - these are created during an earthquake. These fast waves travel through various earth layers.