document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=168020>Question 168020</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Help!<BR>\n" );
document.write( "Is the equation Pressure=force/area a joint variation?  How do you know? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #123844 by </B><A HREF=/tutors/aboutme.mpl?userid=gonzo><B>gonzo(654)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=gonzo><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=123844\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> an excerpt from the web:<BR>\n" );
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document.write( "When we say z is jointly proportional to a set of variables, it means that z is directly proportional to each variable taken one at a time.<BR>\n" );
document.write( "If z varies jointly with respect to x and y, the equation will be of the form z = kxy (where k is a constant).<BR>\n" );
document.write( "Equation: c = 5ab<BR>\n" );
document.write( "Variable c is jointly proportional to a and b. That means c is directly proportional to both a and b.<BR>\n" );
document.write( "Doubling a causes c to double. Doubling b causes c to double. Doubling both a and b causes c to quadruple.<BR>\n" );
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document.write( "based on that definition, the equation as stated would not be joint.<BR>\n" );
document.write( "however, if you move the equation around, then that moved around equation could be considered joint.<BR>\n" );
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document.write( "your equation p = f/a does not fit the form of a joint equation, but it can be changed to read:<BR>\n" );
document.write( "f = a*p<BR>\n" );
document.write( "f = a*p looks like it fits the form of a joint variation if you add a k into it (k = 1 in this case), i.e. f = k*a*p.<BR>\n" );
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document.write( "why f = a*p would be considered joint, while p = f/a would not is beyond me, but that's what the definition states.<BR>\n" );
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document.write( "the proportion has to be direct with each of 2 or more variables taken one at a time, as stated above.<BR>\n" );
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