Rotating fan. Dealing with revolutions, magnitude of acceleration, and period of motion...?

Question

A rotating fan completes 1200 revolutions every minute. Consider the tip of a blade, at a radius of 0.15 m. Here are the questions: (a) Through what distance does the tip move in one revolution? Also, what are (b) the tip's speed and (c) the magnitude of it's acceleration? (d) What is the period of motion? Show and explain your work. Thanks!

Answer 1

1200 revolutions every minute means 20 revolutions per second.
(a) The tip moves 2*pi*r = 2*3.14*0.15m = 0.94m in one revolution.
(b) The tip's speed is (20/s)*0.94m = 19m/s.
(c) The magnitude of it's acceleration is v^2/r = (19m/s)^2/0.15m = 2.4 km/s^2
(d) The period of motion is 1/(20/s) = 0.05s, since it rotates 20 revolutions per second.