A plank of mass 10 kg rests on a smooth horizontal surface. 2 blocks A and B of masses 2 kg and 1 kg respectively lies at a distance of 3 m from each other on a large plank . the friction coefficient between block A and plank is 0.3 and between block B and plank is 0.1 . friction coefficient between ground and plank is zero. now a force of 15 N is applied on the plank in horizontal direction. find the time after which the block A collides with the block B?
how to solve it???
the answer is 6 seconds...