document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=80212>Question 80212</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the half-life of a radioactive element that decays according to the rule: <BR>\n" );
document.write( "dA/dt=-0.014A<BR>\n" );
document.write( "where A is the amount in kg present after t years. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #57551 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=57551\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the half-life of a radioactive element that decays according to the rule: <BR>\n" );
document.write( "dA/dt=-0.014A<BR>\n" );
document.write( "where A is the amount in kg present after t years.<BR>\n" );
document.write( "--------<BR>\n" );
document.write( "Integrating you get A(t)=-0.014At<BR>\n" );
document.write( "If A is doubled you have:<BR>\n" );
document.write( "2A=-0.014At<BR>\n" );
document.write( "2=-0.014t<BR>\n" );
document.write( "t=2/-0.014<BR>\n" );
document.write( "---------<BR>\n" );
document.write( "Comment:<BR>\n" );
document.write( "This would give you a negative value for t.<BR>\n" );
document.write( "I think something is missing in your posting.<BR>\n" );
document.write( "Decay functions are exponential.  Your posting<BR>\n" );
document.write( "does not lead to that conclusion.<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );