A string is wrapped around a wheel as shown in the figure. The wheel can rotate freely about its axis, and the loose end of the string is attached to a block. Assume that the spokes of the wheel have negligible mass, so that the wheel can be modeled as a uniform hollow cylinder. The block and the wheel both have mass m=0.5 kg, and the radius of the wheel is 12 cm. What is the angular acceleration a in rad/s of the wheel once the block is released? (1) 41 (2) 45 (3) 38 (4) 36 (5) 51 m E