document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=211479>Question 211479</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0136007317/algebrahomeworkh>Beginning & Intermediate Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> An object is thrown upward from the top of an 80 foot building with an initial velocity of 64 feet per second. The height h of an object after t seconds is given by the quadratic equation (((h=-16t^2+64t+80))). When will 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 #159840 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><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=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=159840\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An object is thrown upward from the top of an 80 foot building with an initial velocity of 64 feet per second. The height h of an object after t seconds is given by the quadratic equation (((h=-16t^2+64t+80))). When will the object hit the ground.\r<BR>\n" );
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document.write( "Since we're looking for \"h,\" or the height at 0, we then set the equation to 0, and solve for t. We will then have:\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+64t+%2B+80 ALIGN=MIDDLE  ALT=\"0+=+-16t%5E2+%2B+64t+%2B+80\"   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=-16%280%29+=+-16%28t%5E2+-+4t+-+5%29 ALIGN=MIDDLE  ALT=\"-16%280%29+=+-16%28t%5E2+-+4t+-+5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > ------> factoring out the GCF, -16\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+t%5E2+-+4t+-+5 ALIGN=MIDDLE  ALT=\"0+=+t%5E2+-+4t+-+5\"   DISABLED_style= \"max-width:90%; height:auto;\" > -------> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16+=+-16 ALIGN=MIDDLE  ALT=\"-16+=+-16\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "0 = (t - 5)(t + 1)\r<BR>\n" );
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document.write( "Therefore, t = 5, or -1, but t = - 1 is ignored\r<BR>\n" );
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document.write( "This means that the object will hit the ground <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%285%29 ALIGN=MIDDLE  ALT=\"highlight_green%285%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > seconds after being thrown in the air.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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