Wave Equations

Wave Speed

The speed of any wave is the distance travelled by the wave every second.

When it possible to measure the distance travelled by one wave then the standard speed, distance, time equation can be used, for example.

Example 1

Imagine a water wave travelling the length of a 50m swimming pool.

A pupil watches a wave travel the length of the 50m pool in a time of 40 seconds.

The speed of the wave is calculate as;

The Wave Equation

For all waves this equation can be used to calculate wave speed, frequency and wavelength, this equation is often referred to as the wave equation as it only applies to waves.

where :-

      • V = Speed of the wave ( ms-1 )

      • f = Frequency of the wave ( Hz )

        • λ = Wavelength of the wave ( m )

Example 2

A submarine sends out an sound pulse through the sea. The sound has a frequency of 7500Hz and a wavelength of 0.2m.

Determine the speed of the sound through the sea.

Period of a Wave

The Period of a Wave is defined as "The length of time taken for one wave to pass a point". This means that the Period and the Frequency of the wave are closely related. The following formula can be used to calculate the Period of the Wave :-