document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=396663>Question 396663</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do I find when an object hits the ground using the equation: -16t^2 +560t.  I know how to find the height after however many seconds, but cannot figure out how to find this. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #281325 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=281325\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h(t) = -16t^2 +560t<BR>\n" );
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document.write( "h(t) is the height of the object after t seconds.<BR>\n" );
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document.write( "When the object is on the ground the height is zero.<BR>\n" );
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document.write( "Solve:<BR>\n" );
document.write( "-16t^2+560t = 0<BR>\n" );
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document.write( "-16t(t-35) = 0<BR>\n" );
document.write( "t = 0 or t = 35<BR>\n" );
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document.write( "That means the object is on the ground at the beginning<BR>\n" );
document.write( "and it is back on the ground after 35 seconds.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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