1. Consider two pendulums, 1 and 2, with the same string length L, but with different bob masses m1 and m2. They are coupled by a spring of spring constant k, which is attached to the bobs. Find their equations of motion, for small oscillations, solve for the modes and find their frequencies and configurations.

1. A thin disk attached to the end of an elastic beam has three uncoupled modes of vibration. The longitudinal motion, transverse motion and the torsional oscillations are all kinematically independent. Calculate the following for the system shown. a. Longitudinal stiffness b. Transverse stiffness c. Torsional stiffness mumm 65 cm r= 10 mm E-200 x 10° N/m² G=80 x 10º N/m²

A rigid block of mass ? is mounted on four elastic supports, as shown in the figure. A mass ? drops from a height ? and adheres to the rigid block without rebounding. If the spring constant of each elastic support is ?, derive the equation of motion and find the natural frequency of vibration of the system (a) without the mass ?, and (b) with the mass ?. Also, find the resulting motion of the system in case (b). By using lagrange energy method