document.write( "Question 1093873: Please help, can't seem to find a solution:
\n" ); document.write( "The intensity of light (in foot-candle) varies inversely as the square of the distance (in feet) from the light source. The intensity of light 3 feet from the source is 72 foot-candles. How far away is the source if the intensity of light is 2 foot-candles
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Algebra.Com's Answer #708479 by Alan3354(69443)\"\" \"About 
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The intensity of light (in foot-candle) varies inversely as the square of the distance (in feet) from the light source. The intensity of light 3 feet from the source is 72 foot-candles. How far away is the source if the intensity of light is 2 foot-candles
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\n" ); document.write( "What have you tried?
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\n" ); document.write( "The intensity of light (in foot-candle) varies inversely as the square of the distance (in feet) from the light source. The intensity of light 3 feet from the source is 72 foot-candles. How far away is the source if the intensity of light is 2 foot-candles
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\n" ); document.write( "I = k/d^2 where k is a constant.
\n" ); document.write( "72 = k/3^2
\n" ); document.write( "k = 72*9 = 648
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\n" ); document.write( "How far away is the source if the intensity of light is 2 foot-candles
\n" ); document.write( "2 = 648/d^2
\n" ); document.write( "d^2 = 648/2 = 324
\n" ); document.write( "d = 18 ft \n" ); document.write( "
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