document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=493741>Question 493741</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If a stone is tossed from the top of a 250 meter building, the height of the stone as a function of time is given by h(t) = -9.8t2 – 10t + 250, where t is in seconds, and height is in meters. After how many seconds will the stone hit the ground? Round to the nearest hundredth’s place; include units in your answer. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #335444 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=335444\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h(t) = -9.8t2 – 10t + 250<BR>\n" );
document.write( "set h(t) to zero (ground level) and solve for t:<BR>\n" );
document.write( "0 = -9.8t2 – 10t + 250<BR>\n" );
document.write( "0 = 9.8t2 + 10t - 250<BR>\n" );
document.write( "0 = 4.9t2 + 5t - 125<BR>\n" );
document.write( "applying the \"quadratic formula\" we get:<BR>\n" );
document.write( "t = {-5.59, 4.57}<BR>\n" );
document.write( "we can throw away the negative solution leaving:<BR>\n" );
document.write( "t = 4.57 seconds<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );