document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=336880>Question 336880</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The intensity I of light from a light bulb varies inversely as the square of the distance d from the light bulb. Suppose I is 1000 w/m^2 when the distance is 4m. How much farther would it be to a point where the intensity is 810 w/m^2? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #241477 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=241477\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Do it like this one:<BR>\n" );
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document.write( "The intensity I of light from a light bulb varies inversely as the square of the distance d from the light bulb. Suppose I is 640 w/m^2 when the distance is 8m. How much farther would it be to a point where the intensity is 90 w/m^2?<BR>\n" );
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document.write( " k is a constant, d = distance<BR>\n" );
document.write( "640 = k/8^2 = k/64<BR>\n" );
document.write( "k = 40960<BR>\n" );
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document.write( "For 90 w/m^2:<BR>\n" );
document.write( "90 = 40960/d^2<BR>\n" );
document.write( "d^2 = 40960/90<BR>\n" );
document.write( "d = 64/3 meters <BR>\n" );
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