2. A torsional pendulum has a natural frequency of 200 cycles/min when vibrating in vacuum. The mass moment of inertia of the disc is 0.2 kg-m². It is then immersed

in oil and its natural frequency is found to be180 cycles/min. Determine the damping constant. If the disc when placed in oil, is given an initial displacement of 2°, find its displacement at the end of the first cycle.(10 points)