7) The 50kg rod ABCD, with center of mass G, has a radius of gyration 2.4m and is in static equilibrium in the position shown. It is pinned at C and is connected to springs at B and D as shown. (a) For small rotations determine the time period of the resulting motion (22 pts) (b) If a counter-clockwise moment 30 sin(9t) N-m were applied to the rod, determine the amplitude of the steady state response. Indicate if the steady state repsonse is in-phase or our-of-phase. (3 pts) IkN/m ww 2m 20+200 D 4m 2kN/m