document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=40934>Question 40934</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A certain radioactive isotope has a half life of aprox 1600 years. How many years to the nearest year would be required for a given amount of this isotope to decay to 60% of that amount? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #26334 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=26334\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A certain radioactive isotope has a half life of aprox 1600 years. How many years to the nearest year would be required for a given amount of this isotope to decay to 60% of that amount?\r<BR>\n" );
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document.write( "0.60A = A (1/2)^[t/1600]<BR>\n" );
document.write( "0.60=(1/2)^[t/1600}<BR>\n" );
document.write( "log(0.6)=[t/1600]log0.5<BR>\n" );
document.write( "t/1600= log.6/log.5= 0.73696559...<BR>\n" );
document.write( "t=1179.14... yrs.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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