By means of a rope whose mass is negligible, two blocks are suspended over a pulley whose frame is attached to the ceiling. The pulley can be treated as a uniform solid cylindrical disk. One block weighs 11.0-kg, the other block weighs 44.0-kg. The downward acceleration of the 44.0-kg block is observed to be exactly one-half of the acceleration due to gravity. Noting the tension in the rope is not the same on each side of the pulley, find the mass of the pulley.