document.write( "Question 1106811: The maximum load of a horizontal beam that is supported at both ends vari\n" ); document.write( "of the height and inversely as the length between the supports. A beam 6 m long, 0.1 m wide, and 0.06 m high
\n" ); document.write( "supports a load of 360 kg. What is the maximum load supported by a beam 16 m long, 0.2 m wide, and 0.08 m high?
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Algebra.Com's Answer #721809 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The information tells us that the mass m that can be supported by a beam of length l, width w, and height (thickness) h is

\n" ); document.write( "\"m+=+k%28%28w%29%28h%5E2%29%2Fl%29\"

\n" ); document.write( "where k is a constant.

\n" ); document.write( "The value of the constant can be determined from the given information: When the length is 6m, the width is 0.1m, and the height is 0.06m, the maximum load is 360kg. So

\n" ); document.write( "\"360+=+k%28%280.1%29%280.06%5E2%29%2F6%29\"
\n" ); document.write( "\"360+=+k%28.00036%2F6%29+=+k%28.00006%29\"
\n" ); document.write( "\"k+=+6000000\"

\n" ); document.write( "Then using this constant with the new beam measurements,
\n" ); document.write( "\"m+=+6000000%28%280.2%29%280.08%5E2%29%29%2F16\"
\n" ); document.write( "\"m+=+6000000%28.00128%2F16%29+=+480\"

\n" ); document.write( "That is a general method for solving problems like this. But if the numbers are fairly simple, as in this case, I find it easier just to modify the given mass according to each changed dimension of the beam.

\n" ); document.write( "The length of the beam changes from 6m to 16m; since the mass varies inversely as the length, the maximum load decreases by a factor of 6/16 = 3/8.
\n" ); document.write( "The width doubles from 0.1m to 0.2m; since the mass varies directly with the width, the maximum load increases by a factor of 2.
\n" ); document.write( "The height changes from 0.06m to 0.08m; since the mass varies directly with the square of the height, the maximum load increases by a factor of (0.08/0.06)^2 = (4/3)^2 = 16/9.

\n" ); document.write( "Then the new maximum load is
\n" ); document.write( "\"360%2A%283%2F8%29%2A%282%29%2A%2816%2F9%29+=+360%2A%284%2F3%29+=+480\"
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