document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=954507>Question 954507</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a ball is thrown upward with an initial velocity of 64 ft/sec. from a height of 720 ft. its height h, in feet, after t seconds is given by h (t)=-16t^2+64t+720. After how long will the ball reach 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 #582958 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=582958\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a ball is thrown upward with an initial velocity of 64 ft/sec. from a height of 720 ft. its height h, in feet, after t seconds is given by h (t)=-16t^2+64t+720. After how long will the ball reach the ground?<BR>\n" );
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document.write( "When the ball reaches the ground, its height=0<BR>\n" );
document.write( "-16t^2+64t+720=0<BR>\n" );
document.write( "-t^2+4t+45=0<BR>\n" );
document.write( "t^2-4t-45=0<BR>\n" );
document.write( "(t-9)(t+5)=0<BR>\n" );
document.write( "t=9<BR>\n" );
document.write( "After how long will the ball reach the ground? 9 sec </SPAN>\n" );
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