Given that, moment of inertia, 1=1.2‌kg−m2 Initial angular velocity, ω0=0 Initial angular velocity, ω0=0 Angular accelcration, α=30 rad s−2 Final rotational kinetic energy, Kf=1800J Let final angular velocity =ω Using, Kf=
1
2
Iω2 By substituting the values, we get 1800=
1
2
×1.2×ω2 ⇒ω=10√30‌rad∕s We know that, ω=ω0+αl ⇒10√30=0+30t t=