document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=821566>Question 821566</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rocket fired vertically upwards follows the law y=48t-8t^2\r<BR>\n" );
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document.write( "Plot a graph y against t for values of t from 0 to 6 seconds\r<BR>\n" );
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document.write( "By solving the quadratic equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+8t2-48t%2Ba=0 ALIGN=MIDDLE  ALT=\"+8t2-48t%2Ba=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > find the times t1 and t2 when the rocker is at a height of 'a' metres above the launch point. \r<BR>\n" );
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document.write( "Value of a is 25 \r<BR>\n" );
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document.write( "Give final answer correct to 3 decimal places and check the answers using your graph.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #494229 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=494229\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rocket fired vertically upwards follows the law y = 48t-8t2\r<BR>\n" );
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document.write( "Plot a graph y against t for values of t from 0 to 6 seconds<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28400%2C400%2C-10%2C10%2C-10%2C10%2C-8x%5E2%2B48x-25%29 ALIGN=MIDDLE  ALT=\"graph%28400%2C400%2C-10%2C10%2C-10%2C10%2C-8x%5E2%2B48x-25%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "By solving the quadratic equation 8t^2-48t+a = 0 find the times <BR>\n" );
document.write( "t1 and t2 when the rocker is at a height of 'a' metres above <BR>\n" );
document.write( "the launch point. \r<BR>\n" );
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document.write( "Value of a is 25<BR>\n" );
document.write( "t = [48+-sqrt(48^2-4*8*25)]/16 = [48+-38.78]/16<BR>\n" );
document.write( "t1 = 0.5762<BR>\n" );
document.write( "t2 = 5.4238<BR>\n" );
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document.write( "Give final answer correct to 3 decimal places and <BR>\n" );
document.write( "check the answers using your graph.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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