Which of the following is an example of a mechanical wave?

A mechanical wave is characterized by the need for a medium to travel through, which distinguishes it from electromagnetic waves that can propagate through a vacuum. Sound waves are classic examples of mechanical waves; they require a physical medium, such as air, water, or solids, in order to transmit energy. This movement of energy is achieved by the oscillation of the particles in the medium, which allows the sound wave to travel away from the source of the sound.

In contrast, light waves, radio waves, and microwaves are types of electromagnetic waves. These waves do not require a medium to travel and can move through the vacuum of space. This fundamental difference in how they propagate delineates mechanical waves from electromagnetic waves. Thus, the sound wave stands out as the correct example of a mechanical wave.