Question

A fly wheel is rotating with a kinetic energy of 200 J. A constant torque of 4 Nm acts on it to oppose its motion. Before coming to rest, the number of revolutions completed by it is
A. `100//pi`
B. `50//pi`
C. `25//pi`
D. `25//pi`

Answer 1

Correct Answer - C
`KE = tau theta`
`theta = (KE)/(tau)=(200)/(4)=50`
`N = (theta)/(2pi)=(50)/(2pi)=(25)/(pi)`