Question

Why are sound waves called mechanical waves?

Answer 1

Hint: In this question we have been asked to determine why the sound waves are known as mechanical waves as well. To answer this question, we shall study the nature, properties and behaviour of sound waves as well as mechanical waves and apply basic wave principles towards an understanding of sound. We shall also discuss the similarities due to which the sound waves are known as mechanical waves.

Complete answer:
We know that in general a mechanical wave is described as a disturbance that travels through some medium. This disturbance carries energy from one location to another through the medium. The mechanical wave is transported from one point to another due to the disturbance created at the initial point. For example, in a slinky coil the disturbance in the first coil leads to pulling or pushing of the other coils one after the other. In the same way a mechanical wave is transmitted. A mechanical wave is usually generated from a source.
Now, we know that a sound wave is also created due to disturbance in air. Now, considering the tuning fork as the source of sound. When the fork is hit with metal or wooden sticks the air particles near the fork vibrate to a certain frequency creating the vibration in neighbouring particles.
Therefore, similar to the mechanical wave a sound wave 1) has an original source that generates wave 2) the wave is transported through particle-particle interaction 3) requires a medium to transmit the wave.

Therefore, a sound wave is also known as mechanical wave.

Note:
For a sound wave the medium can be air, liquid or any other material through which sound can travel. The vibrations of particles lead to propagation of the sound wave. The other types of waves are the electromagnetic waves. The electromagnetic waves do not require any medium to propagate from one point to another.