A machine of mass 100 kg is subjected to an external harmonic force with a frequency of 40 rad/s. The designer decides to mount the machine on an isolator to reduce the force transmitted to the foundation. The isolator can be considered as a combination of stiffness (K) and damper (damping factor, ζ) in parallel. The designer has the following four isolators:1) k = 640 kN/m, ζ = 0.70 2) k = 640 kN/m, ζ = 0.073) k = 22.5 kN/m, ζ = 0.704) k = 22.5 kN/m, ζ = 0.07Arrange the isolators in the ascending order of the force transmitted to the foundation.

A machine of mass 100 kg is subjected to an external harmonic force wi

1.	A machine of mass 100 kg is subjected to an external harmonic force with a frequency of 40 rad/s. The designer decides to mount the machine on an isolator to reduce the force transmitted to the foundation. The isolator can be considered as a combination of stiffness (K) and damper (damping factor, ζ) in parallel. The designer has the following four isolators:1) k = 640 kN/m, ζ = 0.70 2) k = 640 kN/m, ζ = 0.073) k = 22.5 kN/m, ζ = 0.704) k = 22.5 kN/m, ζ = 0.07Arrange the isolators in the ascending order of the force transmitted to the foundation.
A.	4-3-1-2
B.	3-1-2-4
C.	1-3-2-4
D.	1-3-4-2
Answer» B. 3-1-2-4

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