112. A flywheel has moment of inertia 4 kg

A flywheel has moment of inertia 4 kg-m² and has kinetic energy of 200 J. Calculate the number of revolutions it makes before coming to rest if a constant opposing couple of 5N-m is applied to the flywheel

(a)   12.8 rev

(b)  24 rev

(c)   6.4 rev

(d)  16 rev

Ans. c