document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1048185>Question 1048185</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the problem below using the Exponential Model and population growth.\r<BR>\n" );
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document.write( "a) How much time is needed for a sample of Pd-100 to lose 93.75% of its original amount? Pd-100 has a half-life of 3.634 days. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #663880 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=663880\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (93.75% loss is 15/16) but we will ignore that until checking.<BR>\n" );
document.write( "A=Ao^e^kt<BR>\n" );
document.write( "A/Ao=1/2-e^(-kt)<BR>\n" );
document.write( "ln of both sides<BR>\n" );
document.write( "-0.693=-k(3.634)<BR>\n" );
document.write( "minus signs divide out<BR>\n" );
document.write( "k=0.1907<BR>\n" );
document.write( "A=Ao*e(-0.1907)<BR>\n" );
document.write( "A/Ao=0.0625=e^(-0.1907t)<BR>\n" );
document.write( "ln of both sides<BR>\n" );
document.write( "-2.7726=-0.1907t<BR>\n" );
document.write( "divide by -0.1907<BR>\n" );
document.write( "t=14.54 days<BR>\n" );
document.write( "Check<BR>\n" );
document.write( "This is 4 half-lives, which is 14.546 days.\r<BR>\n" );
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