Longitudinal wave

Definition

A longitudinal wave is a type of wave where the displacement of the medium is parallel to the direction of wave propagation. Sound waves in air are common examples of longitudinal waves.

5 Must Know Facts For Your Next Test

1. In longitudinal waves, particles oscillate back and forth in the same direction as the wave travels.
2. Longitudinal waves consist of compressions (regions of high pressure) and rarefactions (regions of low pressure).
3. The speed of a longitudinal wave depends on the properties of the medium such as density and elasticity.
4. Sound waves are a primary example of longitudinal waves, traveling through mediums like air, water, and solids.
5. The formula for wave speed in a medium is $v = \sqrt{\frac{K}{\rho}}$, where $K$ is the bulk modulus and $\rho$ is the density.

Review Questions

• What is the main difference between longitudinal and transverse waves?
• Describe how particles move in a medium when a longitudinal wave passes through it.
• Explain what happens during compression and rarefaction in a sound wave.

Related terms

Transverse Wave:

A type of wave where particle displacement is perpendicular to the direction of wave propagation, such as light or water waves.

Compression:

A region in a longitudinal wave where particles are closest together, resulting in high pressure.

Rarefaction:

A region in a longitudinal wave where particles are furthest apart, resulting in low pressure.