document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=582213>Question 582213</A>: <I><SPAN STYLE=\"word-break: break-all;\"> After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing. During a storm with 40-knot winds, the wave height after 8 hours was found to be 22 feet, and after 23 hours it was 41 feet.\r<BR>\n" );
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document.write( "(a) Write a linear equation that relates the height to time.\r<BR>\n" );
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document.write( "(b) How long will the wind have been blowing for the waves to be 60 feet heigh? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #372058 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=372058\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing.<BR>\n" );
document.write( " During a storm with 40-knot winds, the wave height after 8 hours was found to be 22 feet, and after 23 hours it was 41 feet.<BR>\n" );
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document.write( "(a) Write a linear equation that relates the height to time.<BR>\n" );
document.write( "find the slope: m = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y2-y1%29%2F%28x2-x1%29 ALIGN=MIDDLE  ALT=\"%28y2-y1%29%2F%28x2-x1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "assign the values as follow<BR>\n" );
document.write( "x1=8,  y1=22<BR>\n" );
document.write( "x2=23, y2=41<BR>\n" );
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document.write( "Find the slope (m)<BR>\n" );
document.write( "m = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y2-y1%29%2F%28x2-x1%29 ALIGN=MIDDLE  ALT=\"%28y2-y1%29%2F%28x2-x1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2841-22%29%2F%2823-8%29 ALIGN=MIDDLE  ALT=\"%2841-22%29%2F%2823-8%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" > is the slope<BR>\n" );
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document.write( "Use the point/slope form to create an equation: y - y1 = m(x - x1)<BR>\n" );
document.write( "y - 22 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >(x - 8)<BR>\n" );
document.write( "y - 22 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >x - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=152%2F15 ALIGN=MIDDLE  ALT=\"152%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >x - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=152%2F15 ALIGN=MIDDLE  ALT=\"152%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 22<BR>\n" );
document.write( "y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >x - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=152%2F15 ALIGN=MIDDLE  ALT=\"152%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=330%2F15 ALIGN=MIDDLE  ALT=\"330%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >x + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=178%2F15 ALIGN=MIDDLE  ALT=\"178%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >; is the equation<BR>\n" );
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document.write( "(b) How long will the wind have been blowing for the waves to be 60 feet height?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=19%2F15 ALIGN=MIDDLE  ALT=\"19%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" >x + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=178%2F15 ALIGN=MIDDLE  ALT=\"178%2F15\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 60<BR>\n" );
document.write( "multiply by 15 to get rid of the denominators<BR>\n" );
document.write( "19x + 178 = 15(60)<BR>\n" );
document.write( "19x = 900 - 178<BR>\n" );
document.write( "19x = 722<BR>\n" );
document.write( "x = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=722%2F19 ALIGN=MIDDLE  ALT=\"722%2F19\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x = 38 hrs to reach 60 ft waves </SPAN>\n" );
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