Vibration Problem (Plot Curve for Amplitude of Vibration; Determine Amplitude of Vibration for Given Motor Speed)

A schematic of a horizontal shaker is shown in figure 1 {see attachment}. The shaker consists of a mass supported on four thin, rectangular springs. The springs are L=200mm long, w=50mm wide and t=4mm thick. The Young's modulus for the springs is 200 GPa. The mass is coupled to the ground via a damper with damping factor C=894Ns/m.

The shaker is driven by a motor with an eccentric mass, mo=50g at an eccentricity of e=150mm. The total mass of the shaker, including motor, is 10kg.

1) Plot the curve for the amplitude of vibration, x to the frequency ration, r for 0<=r<=3.

2) Determine the amplitude of vibration for a motor speed of 1440 rev per min.