Find the natural frequency of vibration of the system if the k1=k2=k3=1 N/m. 11-1 m, 12-2 m, 13=3 m, m=1.8 kg. Bar PQ is rigid and massless. Assume small angular rotation about P. Hint: solve for k12 equivalent first using energy equation then solve for overall equivalent stiffness of k12 and k3 as series springs. Write your final answer in rad/s up to 3 decimal points. Answer: oooo elle k Q 0000 m k3