A uniform disc of mass of 0.50 kg and radius 0.20 m lies on one side initially at rest on a frictionless horizontal surface. A constant force of 3 N is then applied tangentially at its perimeter using a light weight cord wrapped aroutid its edge. What is the (i) angular acceleration (ii) angular velocity and angular displacement after 2s ?

A uniform disc of mass of 0.50 kg and radius 0.20 m lies on one side i

1.	A uniform disc of mass of 0.50 kg and radius 0.20 m lies on one side initially at rest on a frictionless horizontal surface. A constant force of 3 N is then applied tangentially at its perimeter using a light weight cord wrapped aroutid its edge. What is the (i) angular acceleration (ii) angular velocity and angular displacement after 2s ?
Answer» Solution :`tau=Tr = Ialpha = (1//2)mr^(2) xx (a//r) =(1//2) mar, T=(1//2) ma, ma =F-T, F=(3//2)ma, a=2F//3m = 2 xx 3//3 xx 0.5 = 4 m//s^(2), a=a//r = 4//0.2 = 20 "rad/s"^(2) omega = omega_(0) + alphat = 0+20 xx 2 = 40 "rad/s", THETA = (1//2) at^(2) =(1//2) xx 20 xx 2^(2) = 40 "rad"`