document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=442233>Question 442233</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Human hair from a grave in Africa proved to have only 85% of the carbon 14 of living tissue. When was the body buried? The half life of carbon 14 is 5730 years. How many years ago was the body buried? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #305013 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=305013\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Human hair from a grave in Africa proved to have only 85% of the carbon 14 of living tissue. When was the body buried? The half life of carbon 14 is 5730 years. How many years ago was the body buried?<BR>\n" );
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document.write( "A(t) = Ao*(1/2)^(t/5730)<BR>\n" );
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document.write( "0.85*A0 = Ao(1/2)^(t/5730)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "(1/2)^(t/5730) = 0.85<BR>\n" );
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document.write( "(t/5730)*ln(1/2) = ln(0.85)<BR>\n" );
document.write( "t/5730 = ln(0.85)/ln(1/2) = 0.2345<BR>\n" );
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document.write( "t = 5730*0.2345<BR>\n" );
document.write( "t = 1343.49 years<BR>\n" );
document.write( "=============================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "================= </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );