document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1028970>Question 1028970</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half-life of a substance is 12 hours. Find k to complete the formula A = A sub 0 e^kt. After every computation, round to the nearest hundredth.\r<BR>\n" );
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document.write( "Thanks in advance for your help.<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 #644098 by </B><A HREF=/tutors/aboutme.mpl?userid=Cromlix><B>Cromlix(4381)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Cromlix><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=Cromlix><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=644098\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hi there,<BR>\n" );
document.write( "A = Ao e^kt<BR>\n" );
document.write( "Starting wit 10 kg<BR>\n" );
document.write( "Activity drops to half in 12 hours<BR>\n" );
document.write( "5 = 10 e^k12<BR>\n" );
document.write( "5/10 = e^12k<BR>\n" );
document.write( "0.5 = e^12k<BR>\n" );
document.write( "loge0.5 = 12k loge e (loge e = 1)<BR>\n" );
document.write( "k = loge 0.5/12<BR>\n" );
document.write( "k = -0.06<BR>\n" );
document.write( "Hope this helps :-) </SPAN>\n" );
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