Here we run up against a complication. In represents only the part of the linear acceleration that is responsible for changes in the magnitude v of the linear velocity v. Like V. that part of the linear acceleration is tangent to the path of the point in question.
Thus. the linear acceleration of a point on a rotating rigid body has. in general. two components. The radially inward component is present whenever the angular velocity of the body is not zero. The tangential component.
CHECKPOINT 3: A cockroach rides the rim of a rotating merry-go-round. If the angular speed of this system (merry-go-round + cockroach) is constant, does the cockroach have (a) radial acceleration and (b) tangential acceleration? If the angular speed is decreasing, does the cockroach have (c) radial acceleration and (d) tangential acceleration?