A rotor, having a mass moment of inertia \(J_{1}=15 \mathrm{~kg}-\mathrm{m}^{2}\), is mounted at the end of a steel shaft having a torsional stiffness of \(0.6 \mathrm{MN}-\mathrm{m} / \mathrm{rad}\). The rotor is found to vibrate violently when subjected to a harmonic torque of \(300 \cos 200 t \mathrm{~N}-\mathrm{m}\). A tuned absorber, consisting of a torsional spring and a mass moment of inertia ( \(k_{t 2}\) and \(J_{2}\) ), is to be attached to the first rotor to absorb the vibrations. Find the values of \(k_{t 2}\) and \(J_{2}\) such that the natural frequencies of the system are away from the forcing frequency by at least \(20 \%\).