1 , Consider the following rotational system that consists of a rotating bar B] with moment F',%_4_ Fi}; of inertia J1 = 20 Kg :112 and length L; = 2 :11 supported by a spring-damper suspension as shown in Fig. 1 where k = 1200 N/m and b = 50 N sec/m. A rotating machine results in the excitation force t} 2 mum at a distance a: = 1.2 m from the rotating point 0. :1) Compute the transfer function 91(5) F(s where 91(t) is the angular displacement of the bar 3;. b) Compute the worst-case excitation Erequency of that rmults in the maximum steady-state angular displacement of the bar 3;. G(s) = 0) Compute the steady state'amplitude of the angular displacement 61(t) at this excitation frequency w'. To eliminate the vibrations of the System at the worst-case excitation frequency of we include a rotational dynamic vibration absorber 32 with moment of inertia. J1 and length L2 = 0.5 m as shown in Fig. 2. d) Compute the transfer function 91(8) G\") = Fm for the coupled system. e) Determine the value of the moment of inertia J2 that will result in the elimination of the vibrations of the bar B; at the excitation frequency w