The 50-kg flywheel has a radius of gyration about its center of mass of k_o = 250 mm. It rotates with a constant angular velocity of 1200 rev/min before the brake is applied. The coefficient of kinetic friction between the brake pad B and the wheel's rim is u_k = 0.5. A force of P = 300 N is applied to the braking mechanism's handle. Determine the time required to stop the wheel.