(a) Yes, it is possible in the case of a body moving in a circular path with a speed v. The body has a centripetal acceleration directed along the radius of the circular path. The displacement is, however, tangential to the radius i.e., 0 (theta) = 90°. Thus, work done
W = FS cos 90° = 0.
(b) We know that the relation between kinetic energy K and momentum p as