Tangential and Radial Acceleration
Just because an object moves in a circle, it has a centripetal acceleration ac, directed toward the center. We know this centripetal acceleration is given by
ac = v2 / r
This centripetal acceleration is directed along a radius so it may also be called the radial acceleration ar.
If the speed is not constant, then there is also a tangential acceleration at.
The tangential acceleration is, indeed, tangent to the path of the particle's motion.
Circular Motion Relative Motion Return to ToC, 2D Motion (c) 2005, Doug Davis; all rights reserved