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