document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1158307>Question 1158307</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s=-16t+224t. After how many seconds will the ball be 720 feet from the​ ground?\r<BR>\n" );
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document.write( "please help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #781222 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=781222\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "Answer: <font color=red>Either t = 5 seconds or t = 9 seconds</font>\r<BR>\n" );
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document.write( "Work Shown:\r<BR>\n" );
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document.write( "The equation should be <BR>\n" );
document.write( "s = -16t^2 + 224t<BR>\n" );
document.write( "Note the t^2 term as the first term\r<BR>\n" );
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document.write( "Plug in s = 720. Then get everything to one side. Afterward, use the quadratic formula to solve for t.\r<BR>\n" );
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document.write( "s = -16t^2 + 224t<BR>\n" );
document.write( "720 = -16t^2 + 224t<BR>\n" );
document.write( "0 = -16t^2 + 224t - 720<BR>\n" );
document.write( "-16t^2 + 224t - 720 = 0\r<BR>\n" );
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document.write( "Quadratic Formula: Plug in a = -16, b = 224, c = -720<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"t+=+%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"t+=+%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   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=t+=+%28-224%2Bsqrt%28%28224%29%5E2-4%28-16%29%28-720%29%29%29%2F%282%28-16%29%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224%2Bsqrt%28%28224%29%5E2-4%28-16%29%28-720%29%29%29%2F%282%28-16%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-224-sqrt%28%28224%29%5E2-4%28-16%29%28-720%29%29%29%2F%282%28-16%29%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224-sqrt%28%28224%29%5E2-4%28-16%29%28-720%29%29%29%2F%282%28-16%29%29\"   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=t+=+%28-224%2Bsqrt%284096%29%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224%2Bsqrt%284096%29%29%2F%28-32%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-224-sqrt%284096%29%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224-sqrt%284096%29%29%2F%28-32%29\"   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=t+=+%28-224%2B64%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224%2B64%29%2F%28-32%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-224-64%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-224-64%29%2F%28-32%29\"   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=t+=+%28-160%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-160%29%2F%28-32%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+%28-288%29%2F%28-32%29 ALIGN=MIDDLE  ALT=\"t+=+%28-288%29%2F%28-32%29\"   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=t+=+5 ALIGN=MIDDLE  ALT=\"t+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+9 ALIGN=MIDDLE  ALT=\"t+=+9\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "We get two solutions because the ball goes up, but then comes back down again. At t = 5 seconds, the ball is going up. Then at t = 9 seconds, the ball is coming back down. At each of these time values, the height of the ball is 720 feet.\r<BR>\n" );
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