Sound Waves and Their Uses

what is a wave? a wave is a disturbance which travels through a medium and transfers energy from one point to another without causing any permanent displacement of the medium itself. if a stone is dropped in a pond or swimming pool, ripples or waves are seen spreading on the surface of the water from the point where it was dropped. the water itself does not move in the direction of the ripples, but the waves transfers energy from one point to another. there are two major classes of waves ; mechanical and electromagnetic waves .
Mechanical waves are waves that require a material medium for their propagation, such as water waves and sound waves.
Electromagnetic waves are waves that do not require a material medium for their propagation. Examples are light rays, radio waves, x-rays and gamma rays. wave motion
The particle of the medium which transfer energy move to and fro, or vibrate, about a mean position as the wave passes.
A wave is said to be longitudinal if the direction of travel of the wave is the same as the direction of the vibration of the medium
A wave is said to me transverse if the direction of travel of the wave is perpendicular to the direction of the vibration of the medium.
A vibrating tuning fork is capable of creating a longitudinal wave. As the tines of the fork vibrate back and forth, they push on neighbouring air particles. The forward motion of a tine pushes air molecules horizontally to the right and the backward retraction of the tine creates a low-pressure area allowing the air particles to move back to the left. Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure. The diagram below depicts a sound wave created by