document.write( "Question 1205156: A piece of copper is described below:\r
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document.write( "4 in. in length.\r
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document.write( "2 in. wide.\r
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document.write( ".5 in. thick.\r
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document.write( "The piece is formed into a wire of uniform thickness and 100 yds. in length.\r
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document.write( "Determine wire diameter.\r
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document.write( "Not sure how to solve.\r
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Algebra.Com's Answer #841805 by math_tutor2020(3817) ![]() You can put this solution on YOUR website! \n" ); document.write( "1 yard = 3 feet \n" ); document.write( "1 foot = 1/3 of a yard \n" ); document.write( "12 inches = 1/3 of a yard \n" ); document.write( "1 inch = (1/12)*(1/3) of a yard \n" ); document.write( "1 inch = 1/36 of a yard\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Or you could say \n" ); document.write( "1 ft = 12 inches \n" ); document.write( "3 ft = 36 inches = 1 yard \n" ); document.write( "36 inches = 1 yard \n" ); document.write( "1 inch = 1/36 of a yard\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use that last equation to find that \n" ); document.write( "4 inches = 4/36 = 1/9 of a yard \n" ); document.write( "2 inches = 2/36 = 1/18 of a yard \n" ); document.write( "0.5 inches = 0.5/36 = 1/72 of a yard\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then, \n" ); document.write( "volume = (1/9)*(1/18)*(1/72) \n" ); document.write( "volume = 0.00008573 cubic yards\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The wire formed is a cylinder of length 100 yards and radius r. \n" ); document.write( "volume of cylinder = pi*(radius)^2*(height) \n" ); document.write( "V = pi*r^2*h \n" ); document.write( "V = pi*r^2*100 \n" ); document.write( "V = 100pi*r^2 \n" ); document.write( "100pi*r^2 = 0.00008573 \n" ); document.write( "r^2 = 0.00008573/(100pi) \n" ); document.write( "r^2 = 0.000 000 272 887 \n" ); document.write( "r = sqrt(0.000 000 272 887) \n" ); document.write( "r = 0.0005223858727033 \n" ); document.write( "d = diameter \n" ); document.write( "d = 2*r \n" ); document.write( "d = 2*0.0005223858727033 \n" ); document.write( "d = 0.001044771745407 \n" ); document.write( "This measure is in yards.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Multiply by 36 to convert from yards to inches. \n" ); document.write( "You should get roughly 0.03761178 inches.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Another approach:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "volume of initial slab = 4*2*0.5 = 4 cubic inches.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 yard = 36 inches, which means we multiply by 36 to convert from yards to inches. \n" ); document.write( "100 yards = 100*36 = 3600 inches.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Volume of a cylinder = pi*(radius)^2*(height) \n" ); document.write( "V = pi*r^2*h \n" ); document.write( "V = pi*r^2*3600 \n" ); document.write( "V = 3600pi*r^2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3600pi*r^2 = 4 \n" ); document.write( "r^2 = 4/(3600pi) \n" ); document.write( "r^2 = 0.0003 5368 \n" ); document.write( "r = sqrt(0.0003 5368) \n" ); document.write( "r = 0.01880638 \n" ); document.write( "d = 2*r \n" ); document.write( "d = 2*0.01880638 \n" ); document.write( "d = 0.03761276 \n" ); document.write( "We get roughly the same diameter as before. There's a bit of rounding error but the 0.03761 part is the same.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Wire diameter = 0.03761 inches (approximate) \n" ); document.write( "Round this value however needed. \n" ); document.write( "It makes more sense to report the answer in inches rather than yards. But feel free to use yards instead if your teacher requires it. \n" ); document.write( " \n" ); document.write( " |