A disk of radius 12 cm initially at rest begins rotating

Question

Compute each part of given problem:

Problem: A disk of radius 12 cm, initially at rest, begins rotating about its axis with a constant angular acceleration of 8.1 rad/s². What are the following values at t = 5.0 s?

Part A: Find the angular velocity of the disk?

Part B: Find the tangential acceleration at and the centripetal acceleration ac of a point at the edge of the disk?

Please explain clearly with details so that I can follow. Thanks.