An electric fan is turned off, and its angular velocity decreases uniformly from $600re\frac{v}{m}in$ to $150re\frac{v}{m}in$ in $5\mathrm{.}00s.$

Part A

Find the angular acceleration in $re\frac{v}{s^2}.$

Express your answer in revolutions per second squared.

Part B

Find the number of revolutions made by the motor in the $5\mathrm{.}00s$ interval.

Express your answer in revolutions.

$-{}_0$

Part 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$?$

Express your answer in seconds.