A person P of mass 50 kg stands at the middle of a boat of mass 100 kg moving at a constant velocity 10 m/s with no friction between water and boat and also the engine of the boat is shut off. With what velocity (relative to the boat surface) should the person move so that the boat comes to rest. Neglect friction between water and boat.

Options

A. 30 m/s towards right
B. 20 m/s towards right
C. 30 m/s towards left
D. 20 m/s towards left

Answer

A

Explanation

Momentum of the system remains conserved as no external force is acting on the system in horizontal direction. `therefore (50 + 100) 10 = 50 xx V + 100 xx 0 rArr V = 30` m/s towards right, as boat is at rest. `V_(P_("boat")) = 30` m/s