document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=446304>Question 446304</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A projectile is fired upward from a tower 300 feet high with an intial velocity of 320 feet per second.  Its height above ground(h feet)is given at any time(t seconds) by the equation: h=-16t^2+320t+300.  How many seconds will it take the projectile to reach its maximum height?  What is that 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 #307377 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=307377\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A projectile is fired upward from a tower 300 feet high with an initial velocity of 320 feet per second.<BR>\n" );
document.write( " Its height above ground(h feet)is given at any time(t seconds) by the equation: h=-16t^2+320t+300.<BR>\n" );
document.write( " How many seconds will it take the projectile to reach its maximum height?<BR>\n" );
document.write( " :<BR>\n" );
document.write( "Use the axis of symmetry formula to find the time for max height: x=-b/(2a)<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-320%29%2F%282%2A-16%29 ALIGN=MIDDLE  ALT=\"%28-320%29%2F%282%2A-16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-320%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"%28-320%29%2F%28-32%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = +10 seconds it will be at max height<BR>\n" );
document.write( ":<BR>\n" );
document.write( "What is that maximum height?<BR>\n" );
document.write( "Replace t with 10 in the original equation<BR>\n" );
document.write( "h = -16(10^2) + 320(10) + 300<BR>\n" );
document.write( "h = -1600 + 3200 + 300<BR>\n" );
document.write( "h = 1900 ft is the max height<BR>\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );