(15 Points) A system comprised blocks, a light frictionless pulley, and connecting ropes is shown in the figure. The 9.0-kg block is on a perfectly smooth horizontal table.The surfaces of the 12-kg block are rough, with uk = 0.30 between the block and the table. If the 5.0-kg block accelerates downward when it is released, find its acceleration.7.-

Fig: 1

Fig: 2