15-17.The rotor of an electric motor turns at 1750 rom, weighs 150 lb, and has a radius of gyration of 9.5 in. Determine (a) the angular momentum at 1750 rpm and (b) the torque required to slow the rotor to 800 rem in 2 seconds. (=1750 RPM ,m=150lb ,k=9.5EL A)