document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=168270>Question 168270</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0321269470/algebrahomeworkh>Introductory Algebra</A><BR>\n" );
document.write( ": <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 - 16t^2. 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 #124016 by </B><A HREF=/tutors/aboutme.mpl?userid=HyperBrain><B>HyperBrain(694)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=HyperBrain><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=124016\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> By the moment that the object hits the ground, h=0.<BR>\n" );
document.write( "Thus, substituting,\r<BR>\n" );
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document.write( "0=80t-16t<sup>2</sup><BR>\n" );
document.write( "factor out t\r<BR>\n" );
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document.write( "t(80-16t)=0\r<BR>\n" );
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document.write( "t=0    or   80-16t=0<BR>\n" );
document.write( "            16t=80<BR>\n" );
document.write( "              t=5\r<BR>\n" );
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document.write( "SO, it's 0 or 5 seconds.<BR>\n" );
document.write( "HOwever, at t=0, the object is not falling but was about to go up with the initial velocity of 80 ft/sec\r<BR>\n" );
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document.write( "So, the answer is that t=5.\r<BR>\n" );
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document.write( "Power up,<BR>\n" );
document.write( "HyperBrain! </SPAN>\n" );
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