document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=370223>Question 370223</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An angry construction worker throws his wrench downward from a height of 128 feet with an initial velocity of 32 feet per second. The height of the wrench above the ground after seconds is given by S(t) = -16y^2 -32t +128. \r<BR>\n" );
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document.write( "a) What is the height of the wrench after 1 second?\r<BR>\n" );
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document.write( "b) How long does it take for the wrench to reach 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 #263949 by </B><A HREF=/tutors/aboutme.mpl?userid=lefty4ever26><B>lefty4ever26(59)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lefty4ever26><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=lefty4ever26><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=263949\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> S(t)=height.  t = time in seconds.  We want to know height at 1 second.  SO plug in 1 for t. and solve for S(t).<BR>\n" );
document.write( "S(1)=-16(1)^2-32(1)+128=80.  SO at 1 second the wrench is at a height of 80ft.\r<BR>\n" );
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document.write( "The wrench will be at the ground at 0 ft.  So set the equation equal to 0 and solve for t.\r<BR>\n" );
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document.write( "S(t)=-16t^2-32t+128=0<BR>\n" );
document.write( "-16(t^2+2t-8)=0<BR>\n" );
document.write( "-16(t-2)(t+4)=0<BR>\n" );
document.write( "t=2, t=-4  Time can't be negative...so at t=2 seconds the wrench has reached the ground. </SPAN>\n" );
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