A 5.00-kg block is at rest at the top of the inclined plane shown in the diagram. The plane makes an angle of 32.50 with the horizontal. A string is attached to the block and tied around the disk, which has a mass of 2.00 kg and a radius of 8.00 cm. Find the acceleration of the block down the plane if (a) the plane is frictionless, and (b) the plane is rough with a value of μk = 0.54.