Centripetal acceleration arises when an object experiences uniform circular motion. This acceleration is:

Newton's second law for uniform circular motion is: ΣF=ma= - m (v²/r)

IMPORTANT! There is no such thing as a "centripetal force"!!!

When an object undergoes uniform circular motion there is a net force directed toward the center of the circle, but this force has a physical origin, such as gravity, the normal force, tension, or friction.