6) a helicopter blade spins at exactly 100 revolutions per minute. It's tip is 5.00m from the center of it's rotation. (a) calculate the average speed of the blade tip from the helicopters frame of reference. (b) What is it's average velocity over one revolution?
radius of rotation = 5.00m
100 revolutions per minute
a) Average speed = total distance traveled/elapsed time
b) Average Velocity = Δx/Δt = (Xf - Xo)/t
The Attempt at a Solution
a) distance traveled = circumference of rotation
C = ∏d = 31.4m
time elapsed during one rotation = 60s/100 revolutions = 0.6 s/revolution
Therefore each revolution takes 0.6s and the elapsed time would be 0.6s
Average speed = 31.4m/0.6s/revolution = 52.3 m/s/revolution.
I interpret this to mean that the average speed of one revolution is 52.3m/s. Is that the correct way to interpret this result? Is this result even correct? Did I go wrong in my operations?
b) Average velocity = Δx/Δt = 0/0.6s - 0 = 0
I don't think I did this part correctly at all. But if it is a revolution, and this question is based on one revolution, then displacement would be zero, right? you would end up back at the same spot.
Any help would be appreciated.