SOLUTION: I am having trouble with chain unit conversions. Here is the question a DVD spins as fas as 1400 rpm. If the DVD is 4.87 inches in diameter how fast does the outer edge travel at m

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Question 96669: I am having trouble with chain unit conversions. Here is the question a DVD spins as fas as 1400 rpm. If the DVD is 4.87 inches in diameter how fast does the outer edge travel at maximal speed expressed in miles per hour, furlongs and per fortnight. 8 furlongs =1mile 14 days =1 fornight.
do i convert the 4.87 inches to pi then find the miles per hour?
could you show the chain unit conversion? I am finding miles per hour right?
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
a DVD spins as fas as 1400 rpm. If the DVD is 4.87 inches in diameter how fast does the outer edge travel at maximal speed expressed in miles per hour?
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A point on the edge of the DVD will travel
1400*pi*4.87(in/min)(60min/1hr)(1 mi/12*5280 in)
= (1285162.723/63360)(mph)
= 20.28350257 mph
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furlongs and per fortnight. 8 furlongs =1mile 14 days =1 fornight.
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20.28350257 (mi/hr)(8 fur/1 mi)(24 hr/1 day)(14 days/1 fortnight)
= (20.28350257*8*24*14)(furlongs/fortnight)
= 54522.05492(furlongs/fortnight)
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Cheers,
Stan H.