A uniform board of length L and mass M lies near a boundary that separates two regions. In region 1, the coefficient of kinetic friction between the board and the surface is μ1, and in region 2, the coefficient is μ2. The positive direction is shown in the figure.
Find the net work done W by friction in pulling the board directly from region 1 to region 2. Assume that the board moves at a constant velocity.b Express your answer in terms of M, g, L, μ1, and μ2.
What is the total work is done by the external force in pulling the board from region 1 to region 2? (Again, assume that the board moves at a constant velocity.)
Express your answer in terms of M, g, L, μ1, and μ2.
