A block of metal weighing 2 kg is resting on a frictionless plane. It is struck by a jet releasing water at the rate of 1 kgs–1 and with a speed of 5 ms–1. The initial acceleration of the block is

The water jet striking the block at the rate of 1kgs-1 with a speed of 5 ms-1 will exert a force on the block F=vdmdt=5×1=5 NUnder the action of this force of 5 N, the block of mass 2 kg will move with an acceleration given by a=Fm=52=2.5 ms-2