<P> In physics, uniform circular motion describes the motion of a body traversing a circular path at constant speed . Since the body describes circular motion, its distance from the axis of rotation remains constant at all times . Though the body's speed is constant, its velocity is not constant: velocity, a vector quantity, depends on both the body's speed and its direction of travel . This changing velocity indicates the presence of an acceleration; this centripetal acceleration is of constant magnitude and directed at all times towards the axis of rotation . This acceleration is, in turn, produced by a centripetal force which is also constant in magnitude and directed towards the axis of rotation . </P> <P> In the case of rotation around a fixed axis of a rigid body that is not negligibly small compared to the radius of the path, each particle of the body describes a uniform circular motion with the same angular velocity, but with velocity and acceleration varying with the position with respect to the axis . </P> <P> For motion in a circle of radius r, the circumference of the circle is C = 2π r . If the period for one rotation is T, the angular rate of rotation, also known as angular velocity, ω is: </P> <Dl> <Dd> ω = 2 π T = 2 π f = d θ d t (\ displaystyle \ omega = (\ frac (2 \ pi) (T)) = 2 \ pi f = (\ frac (d \ theta) (dt)) \) and the units are radians / second </Dd> </Dl>

What does w stand for in circular motion