document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1011498>Question 1011498</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A solid cylinder dear 8 cm long and of 3.5 cm radius is melted to form a hollow cylinder is melted to form a hollow cylinder of external radius 4 cm and 1 cm thi knees . What is length of hollow cylinder  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #627153 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=627153\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> volume of a cylinder = pi*r^2*h\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the solid cylinder volume = pi*3.5^2*8 = pi*98\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the hollow cylinder has an external radius of 4 cm and an internal radius of 3 cm.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you subtract the volume of the cylinder with 3 cm radius from the volume of the cylinder with 4 cm radius, you are left with a cylinder that has a wall of 1 cm width.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the material from the solid cylinder is then poured into this wall to make it solid.   \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the height is calculated from the following measurements.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the material that will be poured into the wall to make it solid has a volume of 98*pi.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the volume of the cylinder with the radius of 4 cm = pi*4^2*h = 16*pi*h.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the volume of the cylinder with the radius of 3 cm = pi*3^3*h = 9*pi*h.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "subtract 9*pi*h from 16*pi*h and you have a wall wall that is 1 cm thick and has a volume of 7*pi*h.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "you determine the height of this wall by solving the following equation.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "7*pi*h = 98*pi\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "divide both sides of this equation by 7*pi to get h = 98*pi / (7*pi).\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "solve for h to get h = 14 cm.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "here's a picture of what i mean.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "not the best, but  hopefully good enough.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2015/122401.jpg\" alt=\"$$$\" </>\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );