document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=75192>Question 75192</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The equationh=-16t^2+112t  gives the height of an arrow, shot upward from the ground with an initial velocity of 112 ft/s, where t is the time after the arrow leaves the ground.  Find the time it takes for the arrow to reach a height of 180 ft.  \r<BR>\n" );
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document.write( "please show your work </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #53979 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=53979\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> h(t)=-16t^2+112t <BR>\n" );
document.write( "Let the height be 180 ft. then:<BR>\n" );
document.write( "-16t^2+112t-180=0<BR>\n" );
document.write( "4(-4t^2+28t-45)=0<BR>\n" );
document.write( "Use the Quadratic Formula to find \"t\".<BR>\n" );
document.write( "t=[-28+-sqrt(784-4*-4*-45)]/-8<BR>\n" );
document.write( "t=[-28+-8]/-8<BR>\n" );
document.write( "t=-36/-8=4.5 seconds<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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