The disk in a computer drive spins up from rest to a final angular speed of 4900 rpm in 2.20 s. What is the angular acceleration of the disk

Asimply means that over time there was some sort of change.

Aball thrown by ginger is moving upward through the air. diagram a shows a box with a downward arrow. diagram b shows a box with an upward arrow. diagram c shows a box with a downward and upward arrow equal in size. diagram d shows a box with a downward and upward arrow with the downward arrow larger in size. which force diagram represents the forces on the ball? you may neglect the effects of air resistance.

What do we mean by the event horizon of a black hole?