# Angular acceleration

In physics, angular acceleration refers to the time rate of change of angular velocity. As there are two types of angular velocity, namely spin angular velocity and orbital angular velocity, there are naturally also two types of angular acceleration, called spin angular acceleration and orbital angular acceleration respectively. Spin angular acceleration refers to the angular acceleration of a rigid body about its centre of rotation, and orbital angular acceleration refers to the angular acceleration of a point particle about a fixed origin.

Angular acceleration
In SI base unitss−2
Behaviour under
coord transformation
pseudovector
Dimension${\displaystyle {\mathsf {T}}^{-2}}$