A block of mass 1kg is placed over a plank of mass 2kg .The length of the plank is 2m . Coefficient of friction between the block and the plank is 0.5 and the ground over which plank is placed is smooth .A constant force F=30N is applied on the plank in horizontal direction .The time after which the block will seperate from the plank is(g=10m/s^2)
