As shown in the figure, the board with length L = 1.6m and mass m = 3kg is placed on a smooth horizontal plane, the small block with mass m = 1kg is placed on the right end of the board, and the dynamic friction coefficient between the board and the block μ = 0.1. Now, apply a horizontal right tension f to the board, take g = 10m / S2, and find: (1) the maximum tension f to keep the block from falling; (2) if the tension f = 10N is constant, the maximum friction coefficient of the small block can be obtained Maximum speed

As shown in the figure, the board with length L = 1.6m and mass m = 3kg is placed on a smooth horizontal plane, the small block with mass m = 1kg is placed on the right end of the board, and the dynamic friction coefficient between the board and the block μ = 0.1. Now, apply a horizontal right tension f to the board, take g = 10m / S2, and find: (1) the maximum tension f to keep the block from falling; (2) if the tension f = 10N is constant, the maximum friction coefficient of the small block can be obtained Maximum speed

(1) The critical condition for the existence of the maximum pulling force is that the block and the board share the same maximum acceleration, A1 = μ MGM = μ g = 1 & nbsp; m / S2 for the block, f = (M + m) A1 = (3 + 1) × 1 & nbsp; n = 4 & nbsp; n (2) when f = 10 & nbsp; N, the acceleration of the board A2 = f − μ MGM = 10 − 0.1 × 103m / S2 = 3 & nbsp; M / S2 from 12a2t2-12a1t2 = L, the time for the block to slide over the board t = 1.6s, the speed of the block to leave the board V1 = a1t = 1.6m/s answer: (1) the maximum tensile force F to keep the block from falling is 4N; (2) if the tensile force F = 10N is constant, the maximum velocity of the small block is 1.6m/s