## College Physics (4th Edition)

In uniform circular motion, the speed of an object is constant. However, since the direction of the object's motion changes continuously as it moves around the circle, the velocity is not constant. $a_c = \frac{v^2}{r}$ Since the speed $v$ is constant, then the magnitude of the acceleration is also constant. However, the direction of the acceleration always points toward the center of the circle. Since the direction of the acceleration vector changes continuously as the object moves around in a circle, the acceleration is not constant.