# Formula Phase Velocity of a Wave Angular frequency Angular wavenumber

## Phase velocity

`$$ \class{blue}{ v_{\text p} } $$`Unit

`$$ \frac{\mathrm m}{\mathrm s} $$`

Phase velocity indicates the velocity of the points of the same phase. So this could be for example the velocity of a wave crest.

The phase velocity of electromagnetic waves is the speed of light \(c\). (Note, however, that it can be exceeded in the case of matter waves or in waveguides).

## Angular frequency

`$$ \omega $$`Unit

`$$ \frac{\mathrm{rad}}{\mathrm s} $$`

Angular velocity is the phase angle covered by the wave per second.

## Angular wavenumber

`$$ k $$`Unit

`$$ \frac{\mathrm{rad}}{\mathrm{m}} $$`

Wavenumber is related to wavelength \(\lambda\) as follows: \( k ~=~ \frac{2\pi}{\lambda} \).