document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1149917>Question 1149917</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man 1.8m tall walks ways from a lamp post 4m high at a speed of 1.5m/s. How fast in m/s does his shadow lengthen in m/s.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #771387 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=771387\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Draw this as similar triangles<BR>\n" );
document.write( "The height of the post is 4<BR>\n" );
document.write( "the man is 1.8 m high to the right of the post.<BR>\n" );
document.write( "The length of the horizontal leg from post to shadow tip is L<BR>\n" );
document.write( "The shadow length is L-x<BR>\n" );
document.write( "dx/dt, relative to the post is what we want<BR>\n" );
document.write( "we also know that (L-x)/L=1.8/4=0.45<BR>\n" );
document.write( "L-x=0.45L<BR>\n" );
document.write( "x=0.55L<BR>\n" );
document.write( "d/dt 0.55L=dx/dt; and dx/dt is 1.5 m/sec<BR>\n" );
document.write( "dL/dt=1.5/0.55=<BR>\n" );
document.write( "2.73 m/sec  </SPAN>\n" );
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