Question

A block (mass = 59.1 kg) is hanging from a massless cord that is wrapped around a pulley (moment of inertia = 1/2MR² kg · m^2, where M = 6.9 kg is the mass of the pulley and R=1.3 m is its radius ), as the drawing shows. Initially the pulley is prevented from rotating and the block is stationary. Then, the pulley is allowed to rotate as the block falls. The cord does not slip relative to the pulley as the block falls. Assume that the radius of the cord around the pulley remains constant at a value of r=R=1.3 m during the block's descent, and the distance of the block at initial position to the floor is 2.0 m. What is the angular velocity in round per minute when the block drops to the floor? Use g = 10 m/s².

Answer 1