document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=271780>Question 271780</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Rational Expressions and Equations\r<BR>\n" );
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document.write( "A marine biology submarine was searching the water for blue whales at 50 feet below the surface where it experienced a pressure of 21 pounds per square inch.  The pressure of an object varies directly with its distance beneath the surface<BR>\n" );
document.write( "question A. Write the relationship between the pressure and depth, using p to represent pressure, d to represent the depth and k to represent the constant of variation. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #198926 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=198926\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the formula for direct variation is y = k*x\r<BR>\n" );
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document.write( "let y = the pressure.<BR>\n" );
document.write( "let x = the depth.\r<BR>\n" );
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document.write( "you get:\r<BR>\n" );
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document.write( "21 = k*50\r<BR>\n" );
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document.write( "this makes k = 21/50 = .42\r<BR>\n" );
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document.write( "your constant of variation is .42\r<BR>\n" );
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document.write( "at 0 depth, the pressure should be 0.\r<BR>\n" );
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document.write( "based on this formula, the pressure at 0 feet is equal to:\r<BR>\n" );
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document.write( "y = 0*.42 = 0\r<BR>\n" );
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document.write( "this would be additional pressure over the normal pressure of the atmosphere.\r<BR>\n" );
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document.write( "at 10 feet, the pressure would be:\r<BR>\n" );
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document.write( "y = 10*.42 = 4.2 pounds per square inch.\r<BR>\n" );
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document.write( "at 50 feet, the pressure would be:\r<BR>\n" );
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document.write( "y = 50 * .42 = 21 pounds per square inch.\r<BR>\n" );
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document.write( "at 100 feet, the pressure would be:\r<BR>\n" );
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document.write( "y = 100 * .42 = 42 pounds per square inch.\r<BR>\n" );
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document.write( "you can see that as x gets greater, y gets greater which means they are directly proportional.\r<BR>\n" );
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document.write( "here's some additional information on variation for you.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"http://www.purplemath.com/modules/variatn.htm\" target = \"_blank\">http://www.purplemath.com/modules/variatn.htm</a><BR>\n" );
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