SOLUTION: A diagram shows a bike which has a rear wheel, diameter 70 cm, a rear sprocket with a diamter 8 cm, and the front sprocket with a diameter 20 cm. And the center of front sprocket

Algebra ->  Conversion and Units of Measurement -> SOLUTION: A diagram shows a bike which has a rear wheel, diameter 70 cm, a rear sprocket with a diamter 8 cm, and the front sprocket with a diameter 20 cm. And the center of front sprocket       Log On


   



Question 1075815: A diagram shows a bike which has a rear wheel, diameter 70 cm, a rear sprocket with a diamter 8 cm, and the front sprocket with a diameter 20 cm. And the center of front sprocket is 28 cm from the ground. Suppose you were to ride this bike, turning the pedals at a steady rate of 100 rpm. How fast are you traveling, in miles per hour?
Can someone help me how to solve this please? Thank you.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A diagram shows a bike which has a rear wheel, diameter 70 cm, a rear sprocket with a diamter 8 cm, and the front sprocket with a diameter 20 cm. And the center of front sprocket is 28 cm from the ground. Suppose you were to ride this bike, turning the pedals at a steady rate of 100 rpm. How fast are you traveling, in miles per hour?
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100 rpm of the pedals --> 100*20/8 = 250 rpm of the rear wheel.
The bike moves 250*circumference per minute = 250*70*2pi = 35000pi cm/minute
= 0.35pi km/min
= 0.35*pi*60 km/hr = 21*pi km/hr
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Convert to mi/hr