calc
posted by ALISON on .
1)Convert 1/20 of a circle to both degrees and radians.
All I have is 9/180 is what I come up with.
2) what fraction of a circle does 3pi/4 represent?
Is 1/4 correct?
3) a ferries wheel has cars which move at 1.5mph. If the diameter of the wheel is 600 ft, how long will it take to complete one revolution? I use v=rw and get 11rev/50pi min I think I did it right but it wants 1rev/ min?

360/20 = 18 deg and 2pi/20 = 0.1 pi
3 pi/4 / 2 pi = 3/8
1.5 (5280 ft/3600 seconds) = 2.2 feet/second
r = 300 feet (not likely ferris wheel radius is the length of a football field but anyway)
circumference = 2 pi r = 600 pi
time to do 2 pi radians = 600 pi/2.2 = 857 seconds
857 seconds / 60 = 14.3 minutes
This must be the world's biggest and slowest ferris wheel. Are you sure the diameter is not 60 feet?