document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=215948>Question 215948</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/1405802111/algebrahomeworkh>Longman mathematics for IGCSE book1</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> a-A cross- channel hovercraft ferry leaves Dover harbour at 9am travelling at 35km/hour. Find an equation giving d (the distance travelled in km) in terms of t (the time in hours after 9am). Plot the graph of this equatiopn for 0<t<1.\r<BR>\n" );
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document.write( "b-As the hovercraft leaves the harbour, the captain sees a car ferry 5 km ahead travelling in the same direction at 15 km/hour. Find an equation for d in  terms of t for the car ferry. Plot the graph of this equation, and find when the hovercraft catches up with the car ferry.\r<BR>\n" );
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document.write( "Please answer both of the parts. I am having a serious problem in this question.<BR>\n" );
document.write( "Thankyou ver very much indeed.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #163127 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=163127\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a-A cross- channel hovercraft ferry leaves Dover harbour at 9am travelling at 35km/hour. <BR>\n" );
document.write( "Find an equation giving d (the distance traveled in km) in terms of t (the time in hours after 9am).<BR>\n" );
document.write( "d = 35t<BR>\n" );
document.write( " Plot the graph of this equation for 0<1.<BR>\n" );
document.write( "for t = 1 hr; d = 35<BR>\n" );
document.write( "for t = 2 hr; d = 70<BR>\n" );
document.write( "Plot two points; x=1; y=35; and x=2; y=70<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-1%2C+4%2C+-10%2C+80%2C+35x%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-1%2C+4%2C+-10%2C+80%2C+35x%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "you can label your graph as 0 is 9AM; 1 is 10Am, etc<BR>\n" );
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document.write( "b-As the hovercraft leaves the harbour, the captain sees a car ferry 5 km ahead traveling in the same direction at 15 km/hour. Find an equation for d in terms of t for the car ferry.<BR>\n" );
document.write( "Since it has a 5 km head start, the equation is d = 15t + 5<BR>\n" );
document.write( "Plot this one the same way: t = 1; d=20; t = 2; d = 35<BR>\n" );
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document.write( " Plot the graph of this equation, and find when the hovercraft catches up with the car ferry. <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-1%2C+4%2C+-10%2C+80%2C+35x%2C+15x%2B5%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-1%2C+4%2C+-10%2C+80%2C+35x%2C+15x%2B5%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "You can solve the two equations, when they are both the same distance<BR>\n" );
document.write( "35t = 15t + 5<BR>\n" );
document.write( "35t - 15t = 5<BR>\n" );
document.write( "20t = 5<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F20 ALIGN=MIDDLE  ALT=\"5%2F20\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr which is 15 min to catch up, agrees with the graph <BR>\n" );
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document.write( "Did I make this understandable to you? ankor@att.net<BR>\n" );
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document.write( "To find the dist, substitute <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > for t in either equation <BR>\n" );
document.write( "we can use .25 hr<BR>\n" );
document.write( "d = 35t<BR>\n" );
document.write( "d = 35 * .25<BR>\n" );
document.write( "d = 8.75 km<BR>\n" );
document.write( "or<BR>\n" );
document.write( "d = 15t + 5<BR>\n" );
document.write( "d = 15(.25) + 5<BR>\n" );
document.write( "d = 3.75 + 5<BR>\n" );
document.write( "d = 8.75 km<BR>\n" );
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document.write( "Which you would expect when both vessels are at the same point in 15 min<BR>\n" );
document.write( "Change the scale in the graph to see it (the +x axis represents 1 hr)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-.5%2C+1%2C+-4%2C+12%2C+35x%2C+15x%2B5%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-.5%2C+1%2C+-4%2C+12%2C+35x%2C+15x%2B5%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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