# Wave Types

## Wave Forms

Longitudinal – A longitudinal wave has the same direction of vibration, and particle movement, as the direction of travel. A Slinky, the kid’s toy, is one example. The coils in the Slinky are being displaced in the direction of travel.

Credit: Dan Russell

Transverse – A transverse wave is oscillating perpendicular to the direction of travel, unlike the longitudinal wave that is in the same direction of travel. Its particle movement is up-and-down (in the example below) as opposed to the left-to-right movement of the longitudinal wave (in the example above).

Credit: Dan Russell

## Wave Motion

Traveling – A traveling wave, as the name implies, is a wave that is moving. It may be either longitudinal or transverse, but will move in the direction of propagation. The top image is longitudinal, traveling waves. The bottom is a transverse wave.

Credit: Ralph Muehleisen

Standing – A standing wave is a stationary wave, remaining in a constant position. An example might be an ocean wave that has a peak that is constantly five feet from the shoreline, never traveling to the shore. The wave moves up and down, peaking at a few feet above sea level and then dropping a few feet below sea level, always in the same place. A standing wave can form when two waves of equal amplitude and frequency are traveling in opposite directions.

Credit: Dan Russell

## Constructive and Destructive Waves

Constructive Waves –the interference of two or more waves of equal frequency and phase, resulting in their mutual reinforcement and producing a single amplitude equal to the sum of the amplitudes of the individual waves.

Destructive Waves – the interference of two waves of equal frequency and opposite phase, resulting in their cancellation where the negative displacement of one always coincides with the positive displacement of the other.