An electric fan is turned off, and its angular velocity decreases uniformly from 490rev/min to 210rev/min in a time interval of length 4.45s.

A) Find the angular acceleration a in revolutions per second per second.

B) Find the number of revolutions made by the fan blades during the time that they are slowing down in Part A.

C) How many more seconds are required for the fan to come to rest if the angular acceleration remains constant at the value calculated in Part A?