document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1061424>Question 1061424</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This is a word problem for my AlgebraII class that I'm stuck on, because I don't know how to set it up. It's a growth and decay problem of the form A=Pe^rt and the problem is<BR>\n" );
document.write( "In the early 1960's, radioactive strontium-90 was released during atmospheric testing of nuclear weapons, and infiltrated the bones of people alive at the time. If the half life of strontium-90 is 29 years, what fraction of strontium-90 absorbed in 1960 remains in the bones in 2016.<BR>\n" );
document.write( "I don't understand the way the book shows these problems, so if you could help that would be amazing.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #676206 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=676206\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It's a growth and decay problem of the form A=Pe^rt and the problem is<BR>\n" );
document.write( "In the early 1960's, radioactive strontium-90 was released during atmospheric testing of nuclear weapons, and infiltrated the bones of people alive at the time. If the half life of strontium-90 is 29 years, what fraction of strontium-90 absorbed in 1960 remains in the bones in 2016.<BR>\n" );
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document.write( "Not sure how you book wants you to solve these<BR>\n" );
document.write( "decay problems; but here's one way.<BR>\n" );
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document.write( "A(t) = P*e^(rt)<BR>\n" );
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document.write( "Since the half-life is 29 years,<BR>\n" );
document.write( "P*e^(r*29) = (1/2)P<BR>\n" );
document.write( "[e^29]^r = (1/2)<BR>\n" );
document.write( "r = ln(1/2)/ln(e^29) = ln(1/2)/29 = -0.0239<BR>\n" );
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document.write( "Your problem::<BR>\n" );
document.write( "A(6) = P*e^(-0.0239*6)<BR>\n" );
document.write( "A(6) = P*0.8664<BR>\n" );
document.write( "Ans: 87/100 of the original amount remains after 6 years<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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