# Formula Phase Velocity of a Wave Wavelength Period

## Phase velocity

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

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

Phase velocity indicates the velocity of points of the same phase. For example, if you focus on a wave crest, then the phase velocity is the velocity of that wave crest.

The phase velocity of electromagnetic waves is the speed of light \(c\).

## Wavelength

`$$ \lambda $$`Unit

`$$ \mathrm{m} $$`

For example, wavelength is the distance between two wave crests.

## Period

`$$ T $$`Unit

`$$ \mathrm{s} $$`

Period is the time a wave crest takes to travel the distance \(2\pi\).