document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=109443>Question 109443</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Help, I am trying to help my daughter with her homework, don't know what I'm doing.  Hope you can help.\r<BR>\n" );
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document.write( "Calorie consumption problem:  Lansburg's Weather and Health reports data gathered during World War II which shows that people use about 35 more calories per day for each 1 degree drop in the Celsius temp.  At 20 degrees C, a working person uses about 2900 calories per day.<BR>\n" );
document.write( "a)  Explain how you know that the calorie consumption varies linerarly with the temp.  What is the slope?  write the equation.<BR>\n" );
document.write( "b)  How many calories per day would a working person use:<BR>\n" );
document.write( "      in the Sahara Desert wht eht temp is 50 C.<BR>\n" );
document.write( "      in Antarctica in August when the temp is -50 C.<BR>\n" );
document.write( "c)  At what temp does your model predict that a working person would use no calories at all.<BR>\n" );
document.write( "d)  Do you think the linear function gives meaningful answers for temp this hot?  <BR>\n" );
document.write( "e)  Sketch a graph of the function using a reasonable domain. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #79797 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=79797\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Calorie consumption problem: Lansburg's Weather and Health reports data gathered during World War II which shows that people use about 35 more calories per day for each 1 degree drop in the Celsius temp. At 20 degrees C, a working person uses about 2900 calories per day.\r<BR>\n" );
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document.write( "a) Explain how you know that the calorie consumption varies linerarly with the temp. What is the slope? write the equation.<BR>\n" );
document.write( "Why linear?: The use of calories per day changes at a CONSTANT RATE of<BR>\n" );
document.write( "+35 for every -1 change in Celsius temperature.<BR>\n" );
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document.write( "Slope = -35 because as temperature INCREASES one degree calorie use decreases<BR>\n" );
document.write( "by 35.<BR>\n" );
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document.write( "b) How many calories per day would a working person use:<BR>\n" );
document.write( "in the Sahara Desert when the temp is 50 C.<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( "Remember 2900 calories are needed when temp is 20 C.<BR>\n" );
document.write( "You have a slope of -35 and a point (20,2900)<BR>\n" );
document.write( "So, 2900 = -35(20)+b<BR>\n" );
document.write( "b = 2900 + 700 = 3600<BR>\n" );
document.write( "Therefore equation is:<BR>\n" );
document.write( "Calories used = -35(temperature) + 3600<BR>\n" );
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document.write( "Sahara question:<BR>\n" );
document.write( "Cals used = -35(50)+3600 = -1750+3600 = 1850<BR>\n" );
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document.write( "in Antarctica in August when the temp is -50 C.<BR>\n" );
document.write( "Antartica question:<BR>\n" );
document.write( "Cals used = -36(-50)+3600 = 1800+3600 = 6400 calories<BR>\n" );
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document.write( "c) At what temp does your model predict that a working person would use no calories at all.<BR>\n" );
document.write( "0 = -35x + 3600<BR>\n" );
document.write( "-35x = -3600<BR>\n" );
document.write( "x = 102.87 C<BR>\n" );
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document.write( "d) Do you think the linear function gives meaningful answers for temp this hot?<BR>\n" );
document.write( "No.<BR>\n" );
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document.write( "e) Sketch a graph of the function using a reasonable domain.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28400%2C300%2C-50%2C50%2C-500%2C7000%2C-35x%2B3600%29 ALIGN=MIDDLE  ALT=\"graph%28400%2C300%2C-50%2C50%2C-500%2C7000%2C-35x%2B3600%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "==============<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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