Wave Equation

(see Wave Properties for definitions)

v = \lambda f

Where:
v = velocity (m/s)
λ = wavelength (m)
f = frequency (Hz)

Wave velocity is also commonly called wave speed.

The wavelength symbol,λ, is Greek letter lambda.

Frequency units are Hertz (Hz):
\si{Hz} = \si{s^{-1}} = \cfrac{1}{s} = \cfrac{cycles}{second}

Notice that wavelength units (m) multiplied by frequency units (1/s) equals velocity units (m/s).

Relationships in Wave Equation

i) Wavelength is inversely related to frequency.

This is easiest to see for waves that typically have the same speed, such as light or sound (in a given medium).

If a wave’s frequency increases while its speed remains the same, its wavelength decreases.

ii) Wave speed is proportional to wavelength.

If wavelength increases and frequency stays same, wave speed must also increase.

iii) Wave speed is proportional to frequency.

If frequency increases while wavelength stays the same, wave speed must also increase.