document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1138079>Question 1138079</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A scientist begins with 250 grams of a radioactive substance. After 250 minutes, the sample has decayed to 32 grams. Rounding to five significant digits, what is the exponential equation representing this situation. To the nearest minute, what is the half life of this substance? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #756016 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=756016\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A scientist begins with 250 grams of a radioactive substance.<BR>\n" );
document.write( " After 250 minutes, the sample has decayed to 32 grams. Rounding to five significant digits, <BR>\n" );
document.write( "  what is the exponential equation representing this situation.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "the radioactive decay formula: A = Ao*2^(-t/h), where<BR>\n" );
document.write( "A = amt after t time<BR>\n" );
document.write( "Ao = the initial amt<BR>\n" );
document.write( "t = time of decay<BR>\n" );
document.write( "h = half-life of substance<BR>\n" );
document.write( "32 = 250*2^(-250/h)<BR>\n" );
document.write( ":<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=32%2F250 ALIGN=MIDDLE  ALT=\"32%2F250\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 2^(-250/h)<BR>\n" );
document.write( ":<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%2832%2F250%29 ALIGN=MIDDLE  ALT=\"ln%2832%2F250%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = ln(2^(-250/h))<BR>\n" );
document.write( ":<BR>\n" );
document.write( "-2.02557 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-250%2Fh ALIGN=MIDDLE  ALT=\"-250%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >*.6931<BR>\n" );
document.write( "-2.0557h = -250 * .6931<BR>\n" );
document.write( "h = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-173.2867%29%2F%28-2.0557%29 ALIGN=MIDDLE  ALT=\"%28-173.2867%29%2F%28-2.0557%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "h = 84.0 minutes is the half life of this substance?  </SPAN>\n" );
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