The spool weighs 20 lb and has a radius of gyration of k G = 3 in.

Question:

The spool weighs 20 lb and has a radius of gyration of k_G = 3 in. If it is released from rest, determine how far it must drop before the velocity of its center becomes 20 ft/s. The cable is wrapped around the inner hub of the spool and unravels as the spool rotates. Neglect the mass of the cable.