Calculate the moment of inertia of a fly wheel, if its angular velocity is increased from 60 r.p.m. to 180 r.p.m. when 100 J of work is done on it.

Explanation

` W = 100 J, omega_1 = 60 RPM = 1 RPS = 2pi Rad`
`omega_2 = 180 RPM = 3 RPS = 6pi Rad`
Work done , W = 100 J =`1/2 Iomega_2^2 - 1/2 Iomega_1^2`
`therefore 100 = 1/2 I (36 pi^2 - 4pi^2) rArr I = (200)/( 32pi^2)`
`=0.6332 kgm^2 = 0.63 kgm^2 `