document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=652686>Question 652686</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A Little League baseball player throws a ball upward. The height h of the ball (in feet) t seconds after the ball is released is given by the quadratic equation<BR>\n" );
document.write( "h = -16t2 +30t +4\r<BR>\n" );
document.write( "\n" );
document.write( "a)	How long does it take the ball to reach a height of 18ft?<BR>\n" );
document.write( "b)	How long does it take the ball to hit the ground?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #408061 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=408061\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A Little League baseball player throws a ball upward. The height h of the ball (in feet) t seconds after the ball is released is given by the quadratic equation<BR>\n" );
document.write( "h = -16t2 +30t +4 <BR>\n" );
document.write( "a) How long does it take the ball to reach a height of 18ft?<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Solve:<BR>\n" );
document.write( "-16t^2 + 30t + 4 = 18<BR>\n" );
document.write( "----<BR>\n" );
document.write( "-16t^2 + 30t - 14 = 0<BR>\n" );
document.write( "----<BR>\n" );
document.write( "-8t^2 + 15t - 7 = 0<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "t = [-15 +- sqrt(225 - 4*-8*-7)]/(-16)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "t = [-15 +- sqrt(29)]/-16<BR>\n" );
document.write( "---<BR>\n" );
document.write( "t = 0.6 seconds and t = 1.274 seconds<BR>\n" );
document.write( "=================================<BR>\n" );
document.write( "===============<BR>\n" );
document.write( "b) How long does it take the ball to hit the ground?<BR>\n" );
document.write( "Solve: -16t^2 + 30t - 4 = 0<BR>\n" );
document.write( "-8t^2 + 15t - 2 = 0<BR>\n" );
document.write( "t = 1.73 seconds<BR>\n" );
document.write( "===================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "===================\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );