document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=361937>Question 361937</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need a formula to find r ( top radius) of a frustum given h 108cm,R(bottom radius)1.1m weight 8200Kg(density of concrete 2400Kg/m^3 \r<BR>\n" );
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document.write( "I have been given V = 1/3 pi h (R^2+Rr+r^2)\r<BR>\n" );
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document.write( "I am just so stuck !!!!! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #257968 by </B><A HREF=/tutors/aboutme.mpl?userid=Fombitz><B>Fombitz(32388)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Fombitz><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=Fombitz><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=257968\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Convert the weight to volume using the density, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rho ALIGN=MIDDLE  ALT=\"rho\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=W=rho%2AV ALIGN=MIDDLE  ALT=\"W=rho%2AV\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=V=W%2Frho=8200%2F2400=41%2F12 ALIGN=MIDDLE  ALT=\"V=W%2Frho=8200%2F2400=41%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=m%5E3 ALIGN=MIDDLE  ALT=\"m%5E3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( ".<BR>\n" );
document.write( ".<BR>\n" );
document.write( ".<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=V=%281%2F3%29%2Api%2Ah%2A%28R%5E2%2BRr%2Br%5E2%29=41%2F12 ALIGN=MIDDLE  ALT=\"V=%281%2F3%29%2Api%2Ah%2A%28R%5E2%2BRr%2Br%5E2%29=41%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F3%29%2Api%2A0.108%2A%281.1%5E2%2B1.1r%2Br%5E2%29=41%2F12 ALIGN=MIDDLE  ALT=\"%281%2F3%29%2Api%2A0.108%2A%281.1%5E2%2B1.1r%2Br%5E2%29=41%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2%2B1.1r%2B1.21=30.21 ALIGN=MIDDLE  ALT=\"r%5E2%2B1.1r%2B1.21=30.21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2%2B1.1r-30=0 ALIGN=MIDDLE  ALT=\"r%5E2%2B1.1r-30=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Use the quadratic formula,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+%28-1.1+%2B-+sqrt%28+1.1%5E2-4%2A1%2A%28-30%29+%29%29%2F%282%2A1%29+ ALIGN=MIDDLE  ALT=\"r+=+%28-1.1+%2B-+sqrt%28+1.1%5E2-4%2A1%2A%28-30%29+%29%29%2F%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "You'll get two answers, one negative, one positive.<BR>\n" );
document.write( "Only the positive one makes sense here.<BR>\n" );
document.write( "The units for the answer will be meters.<BR>\n" );
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