a It was observed that natural frequency of a torsional pendulumwhen vibrating in vacuum is 280Hz. But, the damping frequency is220Hz when the same pendulum is dipped in an oil of specificgravity 0.9. Find the value of damping factor of the oil. (Hint:There is no damping in case of vacuum)
b A vibratory system weighing 1.5tonnes has the the followingsuccessive amplitudes: 5.00, 3.15, 2.00, 0.75, 0.50, 0.30, 0.20,0.10 mm respectively. The time gap between two successive cycles is0.64s. Draw the displacement-time graph of the system. Also,calculate the damping ratio, natural frequency and stiffness of theassociated spring
