The spool is pinned at its center at O, about which it can spin freely. The radius of the spool is R = 0.15 m, its radius of gyration is ko = 0.11 m, and the mass of the spool is ms = 5 kg. The mass Bis suspended from the periphery of the spool by a chain of negligible mass that moves over the spool without slip. The mass of B is mB = 7 kg. If the system is released from rest, determine the number of revolutions of the spool and the time it takes for mass B to achieve a speed of 10 m/s. Figure P7.30