document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=132887>Question 132887</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this word problem:\r<BR>\n" );
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document.write( "If an object is propelled upward from a height of 128 feet at an initial velocity of 112 feet per second, then its height h after t seconds is given by the equation h=-16t^2+112t+128. After how many seconds does the object hit 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 #97098 by </B><A HREF=/tutors/aboutme.mpl?userid=vleith><B>vleith(2983)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=vleith><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=97098\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given :<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h+=+-16t%5E2+%2B+112t+%2B+128 ALIGN=MIDDLE  ALT=\"h+=+-16t%5E2+%2B+112t+%2B+128\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "When the ball hits the ground, the value of h is 0. So\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+-16t%5E2+%2B+112t+%2B+128 ALIGN=MIDDLE  ALT=\"0+=+-16t%5E2+%2B+112t+%2B+128\"   DISABLED_style= \"max-width:90%; height:auto;\" >   divide through by 16<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+-t%5E2+%2B+7t+%2B+8+ ALIGN=MIDDLE  ALT=\"0+=+-t%5E2+%2B+7t+%2B+8+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "factor the equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+%28-t+%2B+8%29%28t+%2B+1%29 ALIGN=MIDDLE  ALT=\"0+=+%28-t+%2B+8%29%28t+%2B+1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So, either -t+8 = 0  or (t+1) =0<BR>\n" );
document.write( "possible answers are t = 8  and t = -1\r<BR>\n" );
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document.write( "Since t cannot be 'minus time', only t = 8 makes sense.\r<BR>\n" );
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document.write( "Answer t = 8 seconds\r<BR>\n" );
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document.write( "Verify the answer by plugging 8 into the original equation, solve and verify the result is 0. </SPAN>\n" );
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