document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=675528>Question 675528</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward with an initial velocity of 48 feet per second. If the ball started its flight at a height of 8 feet, then its height s at time t can be determined by s(t)=-16t^2+48t+8 where s(t) is measured in feet above the ground and t is the number of seconds of flight.<BR>\n" );
document.write( "1)Determine the time it takes for the ball to attain its maximum height.<BR>\n" );
document.write( "2)What would be the maximum height of the ball?<BR>\n" );
document.write( "3)How long will it take for the ball to 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 #419942 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=419942\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward with an initial velocity of 48 feet per second. If the ball started its flight at a height of 8 feet, then its height s at time t can be determined by s(t)=-16t^2+48t+8 where s(t) is measured in feet above the ground and t is the number of seconds of flight.<BR>\n" );
document.write( "1)Determine the time it takes for the ball to attain its maximum height.<BR>\n" );
document.write( "s(t)=-16t^2+48t+8<BR>\n" );
document.write( "complete the square<BR>\n" );
document.write( "s(t)=-16(t^2-3t+9/4)+8+36<BR>\n" );
document.write( "s(t)=-16(t-3/2)^2+44<BR>\n" );
document.write( "ball to attain its maximum height of 44 ft above the ground at 3/2 or 1.5 sec<BR>\n" );
document.write( "..<BR>\n" );
document.write( "2)What would be the maximum height of the ball?<BR>\n" );
document.write( "maximum height of the ball: 44 ft<BR>\n" );
document.write( "..<BR>\n" );
document.write( "3)How long will it take for the ball to hit the ground?<BR>\n" );
document.write( "ball hits the ground when height=0<BR>\n" );
document.write( "-16t^2+48t+8=0<BR>\n" );
document.write( "use following quadratic formula to solve for t<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a=-16, b=48, c=8<BR>\n" );
document.write( "ans:<BR>\n" );
document.write( "t&#8776;-0.158 (reject, t>0)<BR>\n" );
document.write( "or<BR>\n" );
document.write( "t&#8776;3.158<BR>\n" );
document.write( "the ball will hit the ground in 3.158 sec\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );