A vibrating system has a spring rate of 3 000 lb/in, a damping factor of 55 lb · s/in, and a weight of 800 lb. It is excited by a harmonically varying force F0 = 100 lb at a frequency of 435 cycles per minute.

(a) Calculate the amplitude of the forced vibration and the phase angle between the vibration and the force.

(b) Plot several cycles of the displacement-time and force-time diagrams.