A disk of radius R=3.0 m rotates at an angular velocity =(1.6 + 1.2 t) rad/s, where t is in seconds. At time t=2.0 s.,

A disk of radius R=3.0 m rotates at an angular velocity ω=(1.6 + 1.2 t) rad/s, where t is in seconds. At time t=2.0 s., determine 

a) the angular acceleration and b) the speed v and the components of the acceleration a of a point on the edge of the Disk.