Mechanical Wave Motion and Its Types

Waves can first be classified by whether they require a physical medium to travel through. A mechanical wave needs a material medium -- solid, liquid, or gas -- in order to propagate, since it is the medium's own particles, oscillating about their equilibrium positions and interacting with their neighbours, that actually carry the disturbance forward; sound waves and ripples on a water surface are the two standard examples. A non-mechanical wave, by contrast, needs no medium whatsoever and can travel even through the emptiness of a vacuum; light and the rest of the electromagnetic spectrum (including infra-red radiation) are the standard examples, since electromagnetic waves are self-sustaining oscillations of electric and magnetic fields that do not rely on any material particles at all. Separately from this medium-requirement classification, waves can also be classified by the geometric relationship between the direction the medium's particles vibrate and the …