document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=175474>Question 175474</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An angry construction worker throws his wrench downward from a height of 128 feet <BR>\n" );
document.write( "with an initial velocity of 32 feet per second. The height of the wrench above the ground after t seconds is given by S(t)= - 16t  - 32t - 128.<BR>\n" );
document.write( "a) What is the height of the wrench after 1 second?<BR>\n" );
document.write( "b) How long does it take for the wrench to reach the<BR>\n" );
document.write( "    ground?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #130608 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=130608\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> wrench  thrown downward from a height of 128 feet with an initial velocity<BR>\n" );
document.write( " of 32 feet per second. The height of the wrench above the ground after<BR>\n" );
document.write( " t seconds is given by S(t)= -16t^2 - 32t - 128.<BR>\n" );
document.write( "The formula should be -16t^2 (gravity)<BR>\n" );
document.write( ";<BR>\n" );
document.write( "a) What is the height of the wrench after 1 second?<BR>\n" );
document.write( "Substitute 1 for t and find S(t)<BR>\n" );
document.write( "S(t) = -16(1^2) - 32(1) + 128<BR>\n" );
document.write( "s(t) = -16 - 32 + 128<BR>\n" );
document.write( "S(t) = 80 ft is the height of the wrench after 1 second<BR>\n" );
document.write( ";\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "b) How long does it take for the wrench to reach the ground?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "The ground is S(t) = 0, we want to find t, so we have:<BR>\n" );
document.write( "-16t^2 - 32t + 128 = 0<BR>\n" );
document.write( "Simplify, divide equation by -16, this also changes the signs<BR>\n" );
document.write( "t^2 + 2t - 8 = 0<BR>\n" );
document.write( "Factor this to<BR>\n" );
document.write( "(t+4)(t-2) = 0<BR>\n" );
document.write( "The positive solution:<BR>\n" );
document.write( "t = 2 seconds for the wrench to reach the ground </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );