in rad s^-2. The average angular acceleration over a time interval ?t is given by

The instantaneous acceleration ?(t) is given by

Thus, the angular acceleration is the rate of change of the angular velocity, just as acceleration is the rate of change of velocity.

The translational acceleration of a point on the object rotating is given by

where r is the radius or distance from the axis of rotation. This is also the tangential component of acceleration: it