Use a one-element, finite-element model to approximate the lowest nonzero torsional natural frequency of a uniform shaft of mass density \(ho\), polar moment of inertia \(J\), shear modulus \(G\), and length \(L\) that has a thin disk of mass moment of inertia \(I_{1}\) attached at one end and a thin disk of mass moment of inertia \(I_{2}\) attached at the other end.