document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1029621>Question 1029621</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Use the fact that after 5715 years, a given amount of carbon-14 will have decayed to half the original amount to find the exponential decay model for carbon-14.  In 1947, earthenware jars containing what are known as Dead Sea Scrolls were found by an Arab Bedouin herdsman.  Analysis indicated that the scroll wrappings contained 76% of their original carbon-14.  Estimate the age of the Dead Sea Scrolls.  \r<BR>\n" );
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document.write( "Age in 1947 and age today.   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #644692 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=644692\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use the fact that after 5715 years, a given amount of carbon-14 will have decayed to half the original amount to find the exponential decay model for carbon-14.<BR>\n" );
document.write( " In 1947, earthenware jars containing what are known as Dead Sea Scrolls were found by an Arab Bedouin herdsman.<BR>\n" );
document.write( " Analysis indicated that the scroll wrappings contained 76% of their original carbon-14.<BR>\n" );
document.write( " Estimate the age of the Dead Sea Scrolls.<BR>\n" );
document.write( "Age in 1947 and age today.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "The radioactive decay formula<BR>\n" );
document.write( "A = Ao*2^(-t/h), where<BR>\n" );
document.write( "A = the amt remaining after t time<BR>\n" );
document.write( "Ao = initial amt<BR>\n" );
document.write( "t = time of decay<BR>\n" );
document.write( "h = half-life of the substance<BR>\n" );
document.write( ": <BR>\n" );
document.write( "let Ao = 1<BR>\n" );
document.write( "let A = .76<BR>\n" );
document.write( "1 * 2^(-t/5715) = .76<BR>\n" );
document.write( "Using natural logs<BR>\n" );
document.write( " ln(2^(-t/5715)) = ln(.76)<BR>\n" );
document.write( "log equiv of exponents<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F5715 ALIGN=MIDDLE  ALT=\"-t%2F5715\"   DISABLED_style= \"max-width:90%; height:auto;\" >ln(2) = ln(.76)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F5715+=+ln%28.76%29%2Fln%282%29 ALIGN=MIDDLE  ALT=\"-t%2F5715+=+ln%28.76%29%2Fln%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "use you calc<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F5715 ALIGN=MIDDLE  ALT=\"-t%2F5715\"   DISABLED_style= \"max-width:90%; height:auto;\" > = -.396<BR>\n" );
document.write( "t = -.396 * 5715<BR>\n" );
document.write( "t = 2263 yrs is the age of the Scroll in 1947<BR>\n" );
document.write( "now their age is:<BR>\n" );
document.write( "(2016-1947) + 2263 = 2332 yrs </SPAN>\n" );
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