document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=28346>Question 28346</A>: <I><SPAN STYLE=\"word-break: break-all;\">  A rock falls off a building, and its position after t seconds of free fall is 269-16t2 feet above the ground.  The building is 269 feet tall. \r<BR>\n" );
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document.write( "a.	What is the rock’s velocity at t=3 seconds?<BR>\n" );
document.write( "b.	How long does it take the rock to 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 #15411 by </B><A HREF=/tutors/aboutme.mpl?userid=Paul><B>Paul(988)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Paul><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=15411\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Differenitate:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=dy%2Fdx=-16%5E2%2B269 ALIGN=MIDDLE  ALT=\"dy%2Fdx=-16%5E2%2B269\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "=-32x<BR>\n" );
document.write( "Lim(-32x) ---> -32(3)=-96<BR>\n" );
document.write( "x->3\r<BR>\n" );
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document.write( "a) HENCE, the rock's velocity is -96 at 3 second.\r<BR>\n" );
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document.write( "b) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16x%5E2=-269 ALIGN=MIDDLE  ALT=\"-16x%5E2=-269\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2=16.8125 ALIGN=MIDDLE  ALT=\"x%5E2=16.8125\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x=4.1\r<BR>\n" );
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document.write( "Hence, it takes the rock about 4.1 seconds to hit the ground.<BR>\n" );
document.write( "Paul. </SPAN>\n" );
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