document.write( "Question 417475: The stress in the material of a pipe subject to internal pressure varies jointly with the internal pressure and internal diameter of the pipe and inversely with the thickness of the pipe. The stress is 100 pounds per square inch when the diameter is 5 inches, the thickness is 0.75 inch, and the internal pressure is 25 pounds per square inch. Find the stress when the internal pressure is 40 pounds per square inch if the diameter is 8 inches and the thickness 0.5 inch. \n" ); document.write( "

Algebra.Com's Answer #292261 by josmiceli(19441) $\"\"$ $\"About$

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I use what is called a \"constant of proportionality\" to solve these
\n" ); document.write( "Let $\"k\"$ = constant of proportionality
\n" ); document.write( "given:
\n" ); document.write( "------
\n" ); document.write( " $\"100+=+k%2A%28%2825%2A5%29%2F.75%29\"$
\n" ); document.write( " $\".75%2A100+=+125k\"$
\n" ); document.write( " $\"125k+=+75\"$
\n" ); document.write( " $\"k+=+3%2F5\"$
\n" ); document.write( " $\"k+=+.6\"$
\n" ); document.write( "So, just plug this value in with new values
\n" ); document.write( " $\"S+=+.6%2A%28%2840%2A8%29%2F.5%29\"$
\n" ); document.write( " $\"S+=+1.2%2A40%2A8\"$
\n" ); document.write( " $\"S+=+384\"$
\n" ); document.write( "The new stress is 384 pounds/in2 \n" ); document.write( "

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