A time dependent force F = 3t (F in Newton and t in second) acts on three blocks m 1, m 2 and m 3 kept in contact on a rough ground as shown. Co-efficient of friction between blocks and ground is 0.4. If m 1, m 2 and m 3 are 3 kg, 2 kg and 1 kg respectively, the time after which the blocks started to move is (g = 10 ms–2)
Dear student,
blocks will start to move if the applied force exceeds the limiting friction in 3 cases, so applied force has tobe equated to limiting friction value in all three cases from there we would get our answer.
3t = f1
3t = 0.4*m1g = 0.4*3*10 = 12N
so, t = 4sec
in the same way you can find for other blocks.
thanks.
blocks will start to move if the applied force exceeds the limiting friction in 3 cases, so applied force has tobe equated to limiting friction value in all three cases from there we would get our answer.
3t = f1
3t = 0.4*m1g = 0.4*3*10 = 12N
so, t = 4sec
in the same way you can find for other blocks.
thanks.