What type of waves are sound waves classified as?

Sound waves are classified as longitudinal waves because they involve the vibration of particles in the medium through which they travel in the same direction as the wave. When a sound wave propagates, the particles of the medium (such as air, water, or solids) compress and rarefy, creating areas of high and low pressure. This motion allows sound to travel through the medium, transferring energy without the medium itself moving long distances.

Longitudinal waves differ from transverse waves, where particle displacement is perpendicular to the direction of wave propagation, as seen in water waves or waves on a string. Electromagnetic waves, such as light, do not require a medium to travel and are characterized by their oscillating electric and magnetic fields. Surface waves typically occur at the interface between two media, such as water waves that travel along the surface of the ocean and combine features of both transverse and longitudinal waves. Sound waves fit the definition of longitudinal waves because they depend on the compression and expansion of the particles within a medium.