The angular velocity of a fan blade is 8.4 radians per second. Approximately how many revolutions does the fan blade make in 1.4 minutes?

1 - Using 1 revolution =2*pi radians
2 - 8.4 radians/sec / 2*pi radians =1.3369 revolutions/sec.
3 - 1.4 minutes x 60 seconds =84 seconds
4 - 1.3369 rev/sec x 84 seconds =112.3 revolutions in 1.4 minutes.