document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=287437>Question 287437</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello all, I have an interesting problem here that I'm not sure how to solve correctly.<BR>\n" );
document.write( "The problem involves a rocket being shot into the air where H = Height of the rocket in the given equation. I need to solve for certain conditions etc. but dont know how to write out the equations to rearrange. <BR>\n" );
document.write( "Original Equation is: H= -5t^2 + 20t + 15   where H = Height and t = Time.\r<BR>\n" );
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document.write( "a) What is the maximum height reached by the rocket, at what time does this occur?<BR>\n" );
document.write( "b) Find the time(s) when the rocket is 20 metres above the ground.<BR>\n" );
document.write( "c) How long will it take for the rocket to hit the ground?\r<BR>\n" );
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document.write( "Help with any of the above will be most appreciated.<BR>\n" );
document.write( "Thnaks, -Nick. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #208323 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=208323\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the equation is a quadratic in t\r<BR>\n" );
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document.write( "the graph is a downward opening parabola\r<BR>\n" );
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document.write( "a) H-max is at the vertex of the parabola, which is on the axis of symmetry<BR>\n" );
document.write( "___ general equation for axis of symmetry ___ x = -b / (2a)\r<BR>\n" );
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document.write( "b) plug in 20 for H and use the quadratic formula to find the values of t, one going up and one coming down\r<BR>\n" );
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document.write( "c) same as b) except H=0 ___ only the positive value of t is applicable </SPAN>\n" );
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