__Acceleration Diagram for a Link:__

Consider two points A and B on a rigid link as shown in below figure: Let the point B moves with respect to A, with an angular velocity of ω rad/s and let α rad/s^{2} be the angular acceleration of the link AB.

We know that acceleration of a particle whose velocity changes both in magnitude and direction at any instant has the following two components:

1. The centripetal or radial component which is perpendicular to the velocity of the particle at the given instant.

2. The tangential component which is parallel to the velocity of the particle at the given instant.