From third equation of motion for circular motion ω2−ω02=2αθ where, ω= final angular velocity of particle ω0= initial angular velocity α= angular acceleration and θ= angular displacement Here, ω=rv0rad/s (where, r radius of the circle) ω0=0 (initially particle is at rest) θ=2πn (for n rounds) Substituting these values in Eq. (i), we get (rv0)2−0=2α(2πn)⇒α=4πnr2v02rad/s2