Exercise 2
The blades rotate puch faster than you might expect. Since you could not be present at
this site, you will calculate blade speed using this video: https://youtu.be/Gwe8KZKOiQs
Focus on the tip of one blade and count the number of revolutions it makes in
30 seconds anywhere during the video. You can time it with your phone
stopwatch or with the timer shown at the bottom of the video.
Now, calculate the speed at which the blade tip moves in miles per hour.
Follow the steps below. Be sure to show your work! (Include units in each step)
1. Calculate the revolutions per second. To get it divide the number of
revolutions by 30. (0.5 pt)
Revolutions per second:
2 Now, using the formula below calculate the blade tip speed. (1 pt)
Blade tip speed - sx c
Where s is the revolutions per second and c is the circumference of the
rotation area (c-dz). Refer to the figure below for d and z.
