document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=97604>Question 97604</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Science and medicine. The equation h=-16t^2+112t gives the height of an<BR>\n" );
document.write( "arrow, shot upward from the ground with an initial velocity of 112 ft/s, where t is the time after the arrow leaves the ground. Find the time it takes for the arrow to reach a height of 180 ft.Solve to the nearest thousandth.<BR>\n" );
document.write( " Please help me. I need to show all of the work and I am stumped. I have a horrible problem with word problems.\r<BR>\n" );
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document.write( "Thank you very much for your help. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #71014 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=71014\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The equation h=-16t^2+112t gives the height of an arrow, shot upward from the ground <BR>\n" );
document.write( "with an initial velocity of 112 ft/s, <BR>\n" );
document.write( "where t is the time after the arrow leaves the ground. <BR>\n" );
document.write( "Find the time it takes for the arrow to reach a height of 180 ft.Solve to the nearest thousandth.<BR>\n" );
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document.write( "h(t) = -16t^2+112t<BR>\n" );
document.write( "Let h(t)= 180 ft and solve for \"t\":\r<BR>\n" );
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document.write( "-16t^2+112t=180<BR>\n" );
document.write( "-16t^2+112t-180 = 0<BR>\n" );
document.write( "Divide thru by -4 to get:<BR>\n" );
document.write( "4t^2 -28t + 45 = 0<BR>\n" );
document.write( "Use the quadratic formula to get:\r<BR>\n" );
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document.write( "t = [28 +- sqrt(28^2 - 4*4*45)]/8\r<BR>\n" );
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document.write( "t = [28 +- sqrt64)]/8\r<BR>\n" );
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document.write( "t = [28 +- 8]/8\r<BR>\n" );
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document.write( "t = (28+8)/8 = 4.5 seconds (time when the arrow is on the way down)<BR>\n" );
document.write( "t = (28-8)/8 = 2.5 seconds (time when the arrow is on the way up)\r<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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