NEET2022PhysicsRotational MotionActual
An energy of 484 ~J is spent in increasing the speed of a flywheel from 60 rpm to 360 rpm . The moment of inertia of the flywheel is:
Options
- A0.7 ~kg - m ^2
- B3.22 ~kg - m ^2
- C30.8 ~kg - m ^2
- D0.07 ~kg - m ^2
Correct answer
A. 0.7 ~kg - m ^2
Step-by-step solution
Given, aligned & ₁=60 rpm =60 2 60 =2 rad / s & ₂=360 rpm =360 2 60 =12 rad / s aligned Change in kinetic energy, aligned K . E & = 1 2 I ( ₂^2- ₁^2 ) 484 & = 1 2 I ( ₂+ ₁ ) ( ₂- ₁ ) I & = 484 2 14 10 =0.7 ~kg m ^2 aligned (where, the symbols have their usual meanings)