From her elevated DJ booth at a dance club, Caroline is lowering a 2-kg speaker using a 0.6-kg disk of radius 8 cm as a pulley (Figure). The speaker wire runs straight up from the speaker, over the pulley, and then horizontally across the table. She attaches the wire to the 4-kg amplifier on her tabletop, and then turns to get the other speaker. The table, however, is nearly frictionless, and the whole system begins to move when she lets go.
(a) What is the net torque about the center of the pulley?
(b) What is the total angular momentum of the system 3.5 s after release?
(c) What is the angular momentum of the pulley at this time?
(d) What is the ratio of the angular momentum of each piece of equipment to the angular momentum of the pulley?