document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=507307>Question 507307</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A water tank is being emptied so that the height y (in feet) of the water inside the tank decreases at a linear rate with time t measured in hours past 12 noon. If the height was 15ft at 1pm and 7.5ft at 6pm, find\r<BR>\n" );
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document.write( "(a)the equation relating y to t<BR>\n" );
document.write( "(b)the height at 12 noon<BR>\n" );
document.write( "(c)the total time required to empty the tank </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #340424 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=340424\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A water tank is being emptied so that the height y (in feet) of the water inside the tank decreases at a linear rate with time t measured in hours past 12 noon. If the height was 15ft at 1pm and 7.5ft at 6pm, find:<BR>\n" );
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document.write( "(a)the equation relating y to t<BR>\n" );
document.write( "Find the slope, assign the given values as follows<BR>\n" );
document.write( "t1=1; y1=15<BR>\n" );
document.write( "t2=6; y2=7.5<BR>\n" );
document.write( "m = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%287.5-15%29%2F%286-1%29 ALIGN=MIDDLE  ALT=\"%287.5-15%29%2F%286-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = -1.5 is the slope<BR>\n" );
document.write( "Use the point/slope form: y-y1 = m(x-x1), x=t<BR>\n" );
document.write( "y - 15 = -1.5(t - 1)<BR>\n" );
document.write( "y - 15 = -1.5t + 1.5 + 15<BR>\n" );
document.write( "y = -1.5t + 16.5; is the equation<BR>\n" );
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document.write( "(b)the height at 12 noon<BR>\n" );
document.write( "that occurs when t=0; 16.5 ft<BR>\n" );
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document.write( "(c)the total time required to empty the tank<BR>\n" );
document.write( "That occurs when y = 0<BR>\n" );
document.write( "-1.5t + 16.5 = 0<BR>\n" );
document.write( "-1.5t = -16.5<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-16.5%29%2F%28-1.5%29 ALIGN=MIDDLE  ALT=\"%28-16.5%29%2F%28-1.5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = +11 hrs to empty the tank </SPAN>\n" );
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