Given, M=20kg,R=0.2m, F=20N,ω=50rads−1 θ=6.28rad (for one revolution). We know that, Torque = Moment of inertia × Angular acceleration ⇒τ=I×α ⇒α=
τ
l
=
F×R
MR2
2
=
2F
MR
[∵τ=F×R and Idisc=
1
2
MR2] ⇒α=
2×20
20×(0.2)
=10rad∕s2 In angular terms, third equation of motion, ω2=ω02+2α∆θ ⇒(50)2=(0)2+2×10×∆θ ⇒∆θ=