document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=526590>Question 526590</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A certain radioactive substance has a half-life of 400 years.  If 60 kg is accidently released when will 0.25 kg remain? (assumming it decays continuously)\r<BR>\n" );
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document.write( "Please help me with this one, I'm not even sure where to start! Don't you just love the assignments we get before we actually learn the material!!  I hate to ask for help, but I have no idea how to set this up and calculate it!\r<BR>\n" );
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document.write( "Thank you,<BR>\n" );
document.write( "Tracy </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #348618 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=348618\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the general formula for half-life decay is ___ A = Ao [.5^(t / h)]\r<BR>\n" );
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document.write( "A = amount after decay<BR>\n" );
document.write( "Ao = starting amount<BR>\n" );
document.write( "t = time<BR>\n" );
document.write( "h = half-life\r<BR>\n" );
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document.write( "ln(A / Ao) = (t / h)[ln(.5)] ___ h[ln(A / Ao)] / [ln(.5)] = t </SPAN>\n" );
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