document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1176057>Question 1176057</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A hot bar of iron at 1100 degrees Fahrenheit is quenched in oil at 350 degrees. After 2 minutes, the temperature of the iron is 750 degrees.\r<BR>\n" );
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document.write( "(a) Find the value for k in Newton's Law of Cooling. Round your answer to the nearest thousandth.\r<BR>\n" );
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document.write( "k = ?\r<BR>\n" );
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document.write( "(b) What will the temperature of the iron be after 10 minutes? Round your answer to the nearest degree.\r<BR>\n" );
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document.write( "? degrees Fahrenheit\r<BR>\n" );
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document.write( "(c) How long will it take for the iron to reach 400 degrees? Round your answer to the nearest tenth of a minute.\r<BR>\n" );
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document.write( "? minutes </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #801973 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=801973\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> </font></b></pre>  <BR>\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\"><font face = \"consolas\" color = \"indigo\" size = 3><b>\r\n" );
document.write( "Hi\r\n" );
document.write( "After 2 minutes, the temperature of the iron is 750 degrees.\r\n" );
document.write( "T(t)=Ae^kt + Ts\r\n" );
document.write( "t is time\r\n" );
document.write( "•A is the difference between the initial temperature of the object and the surroundings (1100-350)\r\n" );
document.write( "•k is a constant, the continuous rate of cooling of the object\r\n" );
document.write( "T(2) = 750\r\n" );
document.write( "750=750e^2k + 350\r\n" );
document.write( "400 = 750e^2k\r\n" );
document.write( "ln(400/750)/2 = k = -.314\r\n" );
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document.write( "(b) What will the temperature of the iron be after 10 minutes? \r\n" );
document.write( "T=750e^-3.14 + 350 = 382degrees\r\n" );
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document.write( "(c) How long will it take for the iron to reach 400 degrees?\r\n" );
document.write( "400=750e^(-.314)t + 350\r\n" );
document.write( " ln(50/750)/-.314 = t = 8.6 min \r\n" );
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document.write( "Wish You the Best in your Studies.\r\n" );
document.write( "</font></b></PRE>  <BR>\n" );
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