45. A wheel is rotating with an angular speed of 20 rad/s . It is stopped to rest by applying a constant torque in 4s

A wheel is rotating with an angular speed of 20 rad/s . It is stopped to rest by applying a constant torque in 4s . If the moment of inertia of the wheel about its axis is 0.20 kg-m², then the work done by the torque in two seconds will be

(a)     10 J

(b)      20 J

(c)      30 J

(d)      40 J

Ans. c

(6)