Q.
A wheel of radius R rolls on the ground with a uniform velocity v. The relative acceleration of topmost point of the wheel with respect to the bottom most point is
Centripetal acceleration a=Rv2 towards the centre
Thus acceleration of points A and B is shown in the above figure. ∴ Relative acceleration aAB=aA−aB ⇒aAB=Rv2−R−v2=R2v2