document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=842021>Question 842021</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half-life of carbon-14 is 5730 years. This means that every 5730 years the amount is reduced by 50 percent. Assume there are three milligrams of carbon in a piece of wood. How much carbon-14 will be in the piece of wood 1000 years from now?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #507326 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=507326\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A diagram in a wikipedia article suggests that for dead wood, the portion of carbon as C-14 is 3.6%.  Your piece of wood would have an estimated <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%280.036%29%283%29=0.108 ALIGN=MIDDLE  ALT=\"%280.036%29%283%29=0.108\"   DISABLED_style= \"max-width:90%; height:auto;\" > milligrams of C-14 now.\r<BR>\n" );
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document.write( "DECAY EQUATION<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=Ie%5E%28-kt%29 ALIGN=MIDDLE  ALT=\"A=Ie%5E%28-kt%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, I initial amount, t years, A amount at t years, k a constant, e Euler Number<BR>\n" );
document.write( "Half-Life A=I/2, so equation becomes <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=I%2F2=Ie%5E%28-kt%29 ALIGN=MIDDLE  ALT=\"I%2F2=Ie%5E%28-kt%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F2%29=e%5E%28-kt%29 ALIGN=MIDDLE  ALT=\"%281%2F2%29=e%5E%28-kt%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and we also expect t=5730 for this half-life,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F2%29=e%5E%28-k%2A5730%29 ALIGN=MIDDLE  ALT=\"%281%2F2%29=e%5E%28-k%2A5730%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%281%2F2%29=-k%2A5730%2Aln%28e%29 ALIGN=MIDDLE  ALT=\"ln%281%2F2%29=-k%2A5730%2Aln%28e%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-k%2A5730%2A1=ln%281%2F2%29 ALIGN=MIDDLE  ALT=\"-k%2A5730%2A1=ln%281%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=k=%28-ln%281%2F2%29%29%2F5730 ALIGN=MIDDLE  ALT=\"k=%28-ln%281%2F2%29%29%2F5730\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28k=0.000121%29 ALIGN=MIDDLE  ALT=\"highlight_green%28k=0.000121%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "The decay equation may be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28A=Ie%5E%28-0.000121%2At%29%29 ALIGN=MIDDLE  ALT=\"highlight%28A=Ie%5E%28-0.000121%2At%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Your question specifies a calculable 0.108 milligrams of Carbon 14 at present now, and to find how much will be present for t=1000 years.<BR>\n" );
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document.write( "I=0.108 and t=1000;<BR>\n" );
document.write( "Find A.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28A=%280.108%29e%5E%28-0.000121%2A1000%29%29 ALIGN=MIDDLE  ALT=\"highlight%28A=%280.108%29e%5E%28-0.000121%2A1000%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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