Hello,

To my knowledge there are three types of acceleration when a body (e.g. a rod) is moving in a circle about an axis. These are:

1. Angular acceleration : this is the rate of change of angular velocity.

2. Tangential acceleration : this is the linear acceleration of the system in a tangential direction to the circle and equals the radius times the angular acceleration.

3. Radial/centripetal acceleration : this is the linear acceleration of the system that is directed inwards towards the center of the circle

Hope this helps...