A raft of mass M with a man of mass m aboard stays motionless on the surface of a lake. The man moves a distance `l^'` relative to the raft with velocity `v^'(t)` and then stops. Assuming the water resitance to be negligible, find:
(a) the displacement of the raft 1 relative to the shore,
(b) the horizontal component of the force with which the man acted on the raft during the motion.

Answer

`[(ml)/(M+m),F.=-(mM)/(M+m)(dv)/(dt)]`