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, Vectors and 2D Motion (c) 2002, Doug Davis; all rights reserved