The combined mass of a tractor seat and operator is $75 \mathrm{~kg}$ and the undamped natural frequency of the operator seat is $10 \mathrm{rad} \mathrm{s}^{-1} .$ If the seat suspension damping rate is $600 \mathrm{~N} \mathrm{~m}^{-1} \mathrm{~s}^{-1},$ the damping ratio is

(A) 0.2

(B) 0.4

(C) 0.6

(D) 0.8

The combined mass of a tractor seat and operator is $75 \mathrm{~kg}$ and the undamped natural frequency of the operator seat is $10 \mathrm{rad} \mathrm{s}^{-1} .$ If the seat suspension damping rate is $600 \mathrm{~N} \mathrm{~m}^{-1} \mathrm{~s}^{-1},$ the damping ratio is

(A) 0.2

(B) 0.4

(C) 0.6

(D) 0.8

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