document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=95446>Question 95446</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown upward from the roof of a building 100 m tall with an initial velocityof 20 m/s. When will the ball reach a height of 80 m? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #69472 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=69472\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h=(-g/2)t^2+vt+s ... where g is gravitational acceleration (9.8 in meters), v is initial velocity, and s is starting height\r<BR>\n" );
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document.write( "80=-4.9t^2+20t+100 ... 0=-4.9t^2+20t+20 ... using quadratic equation gives\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=%28-20+%2B-+sqrt%2820%5E2-4%2A%28-4.9%29%2A20%29%29%2F%282%28-4.9%29%29 ALIGN=MIDDLE  ALT=\"t=%28-20+%2B-+sqrt%2820%5E2-4%2A%28-4.9%29%2A20%29%29%2F%282%28-4.9%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > ... t=-0.83 and t=4.91 ... the negative value is not realistic </SPAN>\n" );
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