<PRE><B>Question 472766</B>
How many revolutions per second will a bicycle make at the rate of 10km per hour, if the radius is 2 ft?
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circumference of the wheel = 2(pi)r = 4pi ft
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Convert 10 kph to feet per second
10 (km/hr)[1 hr/3600 sec][1000 meters /km][39.37 inches/1 meter][1 ft/12 in]
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= [10*1*1000*39.37*1]/[1*3600*1*1*12](ft/sec)
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= 9.113426 (ft/sec)
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# of revolutions per second = 9.113426/4 = 2.278..
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Cheers,
Stan H. </PRE>