document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=125190>Question 125190</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The equation h= -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<BR>\n" );
document.write( "reach a height of 180 ft. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #91767 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=91767\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h=+-16t%5E2%2B112t ALIGN=MIDDLE  ALT=\"h=+-16t%5E2%2B112t\"   DISABLED_style= \"max-width:90%; height:auto;\" > is your equation for height.  Since you are given the height of 180 ft., just replace h with 180 and solve it like any other quadratic equation.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16t%5E2%2B112t=180 ALIGN=MIDDLE  ALT=\"-16t%5E2%2B112t=180\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16t%5E2%2B112t-180=0 ALIGN=MIDDLE  ALT=\"-16t%5E2%2B112t-180=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "If you divide through by -4, the coefficients become a little more manageable:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4t%5E2-28t%2B45=0 ALIGN=MIDDLE  ALT=\"4t%5E2-28t%2B45=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "You can use the quadratic formula if you don't want to scratch your head over the factorization of this one, but the factors come out to:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282x-9%29%282x-5%29=0 ALIGN=MIDDLE  ALT=\"%282x-9%29%282x-5%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=9%2F2 ALIGN=MIDDLE  ALT=\"x=9%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=5%2F2 ALIGN=MIDDLE  ALT=\"x=5%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Therefore, the arrow will be 180ft above the ground 2.5 seconds after it is released on the way up, and again at 4.5 seconds on the way down.<BR>\n" );
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