# Angular frequency

In

physics (specifically

mechanics,

**angular frequency** ω (sometimes called

**angular velocity**) is a measure of rotation rate, almost invariably given in units of

radians per

second, or simply s

^{-1} since radians are dimensionless. One revolution is equal to 2π radians, hence

where

*T* is the period and

*f* is the

frequency.

Using angular frequency instead of ordinary frequency is convenient in many applications, as it avoids the excessive appearance of π. In fact, it is used in many fields of physics involving periodic phenomena, such as quantum mechanics and electrodynamics.

For example:

Using 'ordinary' frequency, this equation would be: