All Problems Laws of Conservation
Problem 1.159
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 \(1^{\prime}\) relative to the raft with velocity \(\mathrm{v}^{\prime}(t)\) and then stops. Assuming the water resistance 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.
(a) \(\mathbf{I}=-\frac{m}{M+m} \mathbf{l}^{\prime}\) (b) \(\mathbf{F}=-\frac{m M}{M+m} \frac{d \mathbf{v}^{\prime}}{d t}\)