document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=240303>Question 240303</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If an object is thrown upward with an initial velocity of 80 ft/sec, its height after t sec is given by h = 80t - 16t2 Find the number of seconds before the object hits 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 #176115 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=176115\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If an object is thrown upward with an initial velocity of 80 ft/sec, its height after t sec is given by h = 80t - 16t2 Find the number of seconds before the object hits the ground. <BR>\n" );
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document.write( "That's the time that h = 0.  There are 2 of them, one at t = 0, and the other when the object returns to the ground.<BR>\n" );
document.write( "80t - 16t^2 = 0<BR>\n" );
document.write( "16t^2 = 80t<BR>\n" );
document.write( "t = 0<BR>\n" );
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document.write( "16t = 80<BR>\n" );
document.write( "t = 5 seconds<BR>\n" );
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