9. A system with one degree of freedom is being driven by a forcing function of amplitude 2 kN and frequency 6.2 rad/s. The characteristics of the system are: m=350~kg k=4.5~kN/m c=0.8~kNs/m.

Calculate the:

a) natural frequency of vibration

b) damping ratio

c) frequency ratio

d) amplitude of vibration.