Q16 of 46 Page 247

A man of mass ‘m’ standing on a plank of mass ‘M’ which is placed on a smooth horizontal surface, is initially at rest. The man suddenly starts running on the plank with a speed of ‘v’ m/s with respect to the ground. Find the speed of the plank with respect to the ground.

According to the law of conservation of momentum,

Initial momentum = Final momentum


Initial momentum = 0(because the system is initially at rest, velocity is zero)


0 = mv + MV (V is unknown)


V =


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