2. For the system shown in Figure (2), derive the equation of motion using energy method, knowing that, m=m=m3= 1kg, L=1m, k=k2=100N/m, k3= 160N/m, k4= 250N/m, C= 12 N.s/m, Fo = 610 N, and 2 =20 rad/sec, find: i. The undamped natural frequency (n), ii. The damped natural frequency (d), iii. The amplitude for the steady state response (0), and its phase angle (D), k www a 0 b C H+ mi k1 k2 T M Figure (1) Fo Sin Qt m2 L L A m3 K3 K4 www Figure (2) L