For the system shown in the given Fig. 6 the moment of inertia of the weight \(W\) and the ball about the pivot point is \(I_{o}\). The natural frequency of the system is given by

\(f_{n}=\frac{1}{2 \pi} \sqrt{\frac{K a^{2}-W b}{I_{o}}}\)

The system will vibrate when

(a) \(b

(b) \(b=\frac{K a^{2}}{W}\)

(c) \(b>\frac{K a^{2}}{W}\)

(d) \(\mathrm{a}=0\).

K Fig.6 W b