A weight attached to a spring of stiffness 525 N/m has a viscous damping device. When the weight is displaced and release, the period of vibration is 1.80 s, and the ratio of consecutive amplitudes is 4.2 to 1.0. Determine the amplitude and phase when a force F = 2cos3t acts on the system. The answers are 0.797 cm and 51.43 degrees.