The Wave Equation
- The wave equation links the speed, frequency and wavelength of a wave
- This is relevant for both transverse and longitudinal waves
- The wave equation shows that for a wave of constant speed:
- As the wavelength increases, the frequency decreases
- As the wavelength decreases, the frequency increases
The relationship between frequency and wavelength of a wave
Worked example
The wave in the diagram below has a speed of 340 m s–1.
What is the wavelength of the wave?
Examiner Tip
You may also see the wave equation be written as c = fλ where c is the wave speed.However, c is often used to represent a specific speed - the speed of light (3 × 108 m s-1). Only electromagnetic waves travel at this speed, therefore it’s best practice to use v for any speed that isn’t the speed of light instead.
