SOLUTION: The radii of the pedal sprocket, the wheel sprocket, and the wheel of the bicycle are 4 inches, 2 inches, and 14 inches, respectively. A cyclist is pedaling at a rate of 1 revoluti

Algebra ->  Trigonometry-basics -> SOLUTION: The radii of the pedal sprocket, the wheel sprocket, and the wheel of the bicycle are 4 inches, 2 inches, and 14 inches, respectively. A cyclist is pedaling at a rate of 1 revoluti      Log On


   



Question 772050: The radii of the pedal sprocket, the wheel sprocket, and the wheel of the bicycle are 4 inches, 2 inches, and 14 inches, respectively. A cyclist is pedaling at a rate of 1 revolution per second.
Question:
Find the speed of the bicycle in feet per second and miles per hour.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
The radii of the pedal sprocket, the wheel sprocket, and the wheel of the bicycle are 4 inches, 2 inches, and 14 inches, respectively. A cyclist is pedaling at a rate of 1 revolution per second.
Find the speed of the bicycle in feet per second and miles per hour.
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4-inch pedal sprocket rotates at 1 rev/sec
2-inch wheel sprocket rotates at twice the rate of the pedal sprocket=2 rev/sec
14 inch wheel rotates 2/14=1/7 the rate of the wheel sprocket=2/7 rev/sec
..
%28%282%2F7%29+rev%2Fsec%29%2A%282pi%2814%29+inches%2Frev%29%2A%28ft%2F12+inches%29
inches and rev cancel out
(2/7)(28pi)/12=8pi/12=2pi/3=2.09 ft/sec
..
%28%282pi%2F3%29+ft%2Fsec%29%2A%283600+sec%2Fhr%29%2A%28mi%2F5280+ft%29
sec and ft cancel out
2pi*3600/3*5280=1.42 mi/hr
..
speed of the bicycle=2.09 ft/sec or 1.42 mi/hr