document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=61621>Question 61621</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward from the top of a building 112 feet tall with an initial velocity of 96 feet per second.  The distance s (in feet) of the ball from the ground after t seconds is s=112+96t-16t^2.  After how many seconds will the ball pass the top of the building on its way down?  \r<BR>\n" );
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document.write( "I BELIEVE I WOULD USE THE Distance=Rate X Time<BR>\n" );
document.write( "Is that right? Is this how I would start it?<BR>\n" );
document.write( "112+96t-16t^2=r x t.....i got stuck </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #42418 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><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=42418\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The use of the distance formula, d = rt, is not appropriate for this kind of problem. The reason is the distance formula applies in cases of constant motion (speed) whereas this problem involves acceleration (due to gravity).<BR>\n" );
document.write( "You have the appropriate function of distance (really height) as a function of time.<BR>\n" );
document.write( " The question here is...when will the ball reach a height (distance) of 112 feet after being thrown upward?  <BR>\n" );
document.write( "To find out, wou want to set the given function of s(t) equal to 112 ft. and solve for the time, t.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=112+%2B+96t+-+16t%5E2+=+112 ALIGN=MIDDLE  ALT=\"112+%2B+96t+-+16t%5E2+=+112\"   DISABLED_style= \"max-width:90%; height:auto;\" > Subtract 112 from both sides.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=96t+-+16t%5E2+=+0 ALIGN=MIDDLE  ALT=\"96t+-+16t%5E2+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Factor out a t.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%2896+-+16t%29+=+0 ALIGN=MIDDLE  ALT=\"t%2896+-+16t%29+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Apply the zero product principle.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+0 ALIGN=MIDDLE  ALT=\"t+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=96+-+16t+=+0 ALIGN=MIDDLE  ALT=\"96+-+16t+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "At t = 0 seconds, the ball is at 112 feet because that the initial height of the throw.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=96+-+16t+=+0 ALIGN=MIDDLE  ALT=\"96+-+16t+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Add 16t to both sides.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=96+=+16t ALIGN=MIDDLE  ALT=\"96+=+16t\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by 16.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+6 ALIGN=MIDDLE  ALT=\"t+=+6\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The ball will be at 112 feet again in 6 seconds. </SPAN>\n" );
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