document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1207285>Question 1207285</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A model rocket is launched upward with an initial velocity of 270 feet per second. The height, in feet, of the rocket t seconds after the launch is given by<BR>\n" );
document.write( "h = −16t2 + 270t.<BR>\n" );
document.write( "How many seconds after the launch will the rocket be 390 feet above the ground? Round to the nearest tenth of a second. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #845067 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=845067\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h+=+-16t%5E2+%2B+270t ALIGN=MIDDLE  ALT=\"h+=+-16t%5E2+%2B+270t\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Now, we have to find out the time when <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h+=+390 ALIGN=MIDDLE  ALT=\"h+=+390\"   DISABLED_style= \"max-width:90%; height:auto;\" > feet.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=390+=+-16t%5E2+%2B+270t ALIGN=MIDDLE  ALT=\"390+=+-16t%5E2+%2B+270t\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=390+%2B16t%5E2+-+270t=0 ALIGN=MIDDLE  ALT=\"390+%2B16t%5E2+-+270t=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16t%5E2+-+270t%2B390+=0 ALIGN=MIDDLE  ALT=\"16t%5E2+-+270t%2B390+=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-%28-270%29%2B-sqrt%28%28-270%29%5E2-4%2A16%2A390%29%29%2F%282%2A16%29 ALIGN=MIDDLE  ALT=\"t=%28-%28-270%29%2B-sqrt%28%28-270%29%5E2-4%2A16%2A390%29%29%2F%282%2A16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28270%2B-sqrt%2847940%29%29%2F32 ALIGN=MIDDLE  ALT=\"t=%28270%2B-sqrt%2847940%29%29%2F32\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28270%2B-218.95%29%2F32 ALIGN=MIDDLE  ALT=\"t=%28270%2B-218.95%29%2F32\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=1.6 ALIGN=MIDDLE  ALT=\"t=1.6\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=15.3 ALIGN=MIDDLE  ALT=\"t=15.3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "answer is: <BR>\n" );
document.write( " the rocket will be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=390 ALIGN=MIDDLE  ALT=\"390\"   DISABLED_style= \"max-width:90%; height:auto;\" > feet above the ground\r<BR>\n" );
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document.write( "in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=1.6 ALIGN=MIDDLE  ALT=\"t=1.6\"   DISABLED_style= \"max-width:90%; height:auto;\" > seconds on the way up, and\r<BR>\n" );
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document.write( "in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=15.3 ALIGN=MIDDLE  ALT=\"t=15.3\"   DISABLED_style= \"max-width:90%; height:auto;\" > seconds on the way down\r<BR>\n" );
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document.write( " </SPAN>\n" );
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