document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1162031>Question 1162031</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A stone is thrown directly upward from a height of 30 ft, with an initial velocity of 60 ft/sec. The height of the stone, in feet, t seconds after it has been thrown, is given by the function: s(t) = -16t^2 + 60t + 30.\r<BR>\n" );
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document.write( "Based on this model, what is the stone's maximum height? Also, how long does it take for the stone to reach its maximum height? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #785708 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=785708\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h=-16t^2+60t+30<BR>\n" );
document.write( "vertex is at t=-b/2a=-60/-32<BR>\n" );
document.write( "a is the coefficient of the t^2 term or -16<BR>\n" );
document.write( "b is the coefficient of the t term or 60<BR>\n" );
document.write( "so -b/2a=-60/2(-16)<BR>\n" );
document.write( "=60/32 seconds or 1.875 seconds<BR>\n" );
document.write( "f(1.875)=86.25 feet\r<BR>\n" );
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