document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=777517>Question 777517</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Use the formula <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h=+-16t%5E2+%2B+%28vo%29%28t%29 ALIGN=MIDDLE  ALT=\"h=+-16t%5E2+%2B+%28vo%29%28t%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "A ball is thrown straight upward with an initial speed of vo= 40 ft/s.\r<BR>\n" );
document.write( "\n" );
document.write( "(a) When does the ball reach a height of 24 ft?<BR>\n" );
document.write( "(b) When does the ball reach a height of 48 ft?<BR>\n" );
document.write( "(c) What is the greatest height reached by the ball?<BR>\n" );
document.write( "(d) When does the ball reach the highest point of its path?<BR>\n" );
document.write( "(e) When does the ball hit the ground? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #474129 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=474129\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use the formula <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h=+-16t%5E2+%2B+%28vo%29%28t%29 ALIGN=MIDDLE  ALT=\"h=+-16t%5E2+%2B+%28vo%29%28t%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "A ball is thrown straight upward with an initial speed of vo= 40 ft/s.\r<BR>\n" );
document.write( "\n" );
document.write( "(a) When does the ball reach a height of 24 ft?<BR>\n" );
document.write( "Solve -16t^2+40t-24 = 0<BR>\n" );
document.write( "-2t^2+5t-3 = 0<BR>\n" );
document.write( "2t^2-5t+3 = 0<BR>\n" );
document.write( "t = [5+-sqrt(1)]/4<BR>\n" );
document.write( "t = 3/2 seconds<BR>\n" );
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document.write( "(b) When does the ball reach a height of 48 ft?<BR>\n" );
document.write( "(c) What is the greatest height reached by the ball?<BR>\n" );
document.write( "Vertex occurs when x = -b/(2a) = -40/-32 = 5/4<BR>\n" );
document.write( "height = h(10) = -16*(5/4)^2 + 40(5/4) = -25+50 = 25 ft<BR>\n" );
document.write( "---------------------------------------<BR>\n" );
document.write( "(d) When does the ball reach the highest point of its path?<BR>\n" );
document.write( "t = 5/4 seconds<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "(e) When does the ball hit the ground?<BR>\n" );
document.write( "Solve: -16t^2 + 40t = 0<BR>\n" );
document.write( "Factor::<BR>\n" );
document.write( "8t(-2t+5) = 0<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "t = 5/2 = 2.5 seconds<BR>\n" );
document.write( "=========================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "================ </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );