document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1152999>Question 1152999</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A wooden artifact from an archaeological dig contains 80 percent of the Carbon-14 that is present in living trees. To the nearest year, about how many years old is the artifact? (The half-life of Carbon-14 is 5730 years.)<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 #775165 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=775165\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A wooden artifact from an archaeological dig contains 80 percent of the Carbon-14 that is present in living trees.<BR>\n" );
document.write( "To the nearest year, about how many years old is the artifact?<BR>\n" );
document.write( " (The half-life of Carbon-14 is 5730 years.)<BR>\n" );
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document.write( "The radiation decay formula<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A+=+Ao%2A2%5E%28-t%2Fh%29 ALIGN=MIDDLE  ALT=\"A+=+Ao%2A2%5E%28-t%2Fh%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, where<BR>\n" );
document.write( "A = resulting amt after t time<BR>\n" );
document.write( "Ao = initial amt of the substance<BR>\n" );
document.write( "t = time of decay<BR>\n" );
document.write( "h = half-life of substance<BR>\n" );
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document.write( "let Ao = 10 and A = 8<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10%2A2%5E%28-t%2F5730%29+=+8 ALIGN=MIDDLE  ALT=\"10%2A2%5E%28-t%2F5730%29+=+8\"   DISABLED_style= \"max-width:90%; height:auto;\" >; (t is the numerator)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%5E%28-t%2F5730%29+=+8%2F10 ALIGN=MIDDLE  ALT=\"2%5E%28-t%2F5730%29+=+8%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%5E%28-t%2F5730%29+=+.8 ALIGN=MIDDLE  ALT=\"2%5E%28-t%2F5730%29+=+.8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "using natural logs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F5730 ALIGN=MIDDLE  ALT=\"-t%2F5730\"   DISABLED_style= \"max-width:90%; height:auto;\" >ln(2) = ln(.8)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-t%2F5730%29+=+ln%28.8%29%2Fln%282%29 ALIGN=MIDDLE  ALT=\"%28-t%2F5730%29+=+ln%28.8%29%2Fln%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "using your calc<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-t%2F5730%29+=+-.3219 ALIGN=MIDDLE  ALT=\"%28-t%2F5730%29+=+-.3219\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = -5730 * -3219<BR>\n" );
document.write( "t = 1845 yrs\r<BR>\n" );
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