A system comprised blocks, a light frictionless pulley, and connecting ropes is shown in the figure. The B block has a mass of 9.5 kg and is on a perfectly smooth horizontal table. The surfaces of the A block, which has a mass of 10.5 kg, are rough, with l = 0.31 between the block and the table. If the C block with mass 7.2 kg accelerates downward when it is released, find its acceleration. A

A system comprised blocks, a light frictionless pulley, and connecting ropes is shown in the figure. The B block has a mass of 9.5 kg and is on a perfectly smooth horizontal table. The surfaces of the A block, which has a mass of 10.5 kg, are rough, with l = 0.31 between the block and the table. If the C block with mass 7.2 kg accelerates downward when it is released, find its acceleration. A