For the system of blocks and pulley shown, the acceleration of the blocks is a and the friction force acting on the 10 kg block is F. Choose the correct result. Take μ = 0.6 and g = 10 m s⁻².

Question

G1 Physics · Accepted Answer

If the system stays at rest, the 4 kg hanging block gives T = 4g = 40 N. The 10 kg block then needs 40 N static friction. Maximum static friction is μN = 0.6×10×10 = 60 N, so 40 N is available without slipping. Hence a = 0 and friction = 40 N.