document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=431079>Question 431079</A>: <I><SPAN STYLE=\"word-break: break-all;\"> height of rocket launched from platform 12 meters above ground is modeled by function h=-1.4t+25t+12 where h represents height of rocket in meters and t represents number of seconds after launching. how many seconds after launching will rocket return to ground? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #299270 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=299270\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "No.\r<BR>\n" );
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document.write( "The height of a projectile in meters, <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large t\"> seconds after being launched from an initial height of <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large h_o\"> at an initial vertical velocity of <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large v_o\"> is given by:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ h(t)\ =\ -4.9t^2\ +\ v_ot\ +\ h_o\">\r<BR>\n" );
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document.write( "presuming, of course, that all of this activity is occuring in the vicinity of the planet Earth.  I can't imagine where you came up with a -1.4 as a lead coefficient (too big for the moon and too small for Mercury or Mars...maybe one of Jupiter's moons) and I can't imagine how you can have distance as a function of time with a constant acceleration without having a squared variable.\r<BR>\n" );
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document.write( "Your problem has an initial velocity of 25 meters/second and an initial height of 12 meters, so:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ h(t)\ =\ -4.9t^2\ +\ 25t\ +\ 12\">\r<BR>\n" );
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document.write( "You are concerned with finding the positive value of <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large t\"> when the projectile returns to the ground which is typically considered to be 0 height.\r<BR>\n" );
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document.write( "Hence:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ h(t)\ =\ 0\">\r<BR>\n" );
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document.write( "which is to say:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ -4.9t^2\ +\ 25t\ +\ 12\ =\ 0\">\r<BR>\n" );
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document.write( "Just use the quadratic formula to solve the quadratic for the positive root.\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi} + 1 = 0\"><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it<BR>\n" );
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