document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1194516>Question 1194516</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rock is dropped off a cliff 115 m high, how long does it take for the rock to reach the ground?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #826729 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3817)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><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=826729\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "The meters version of the free-fall formula is this approximate equation<BR>\n" );
document.write( "y = 4.9x^2<BR>\n" );
document.write( "where,<BR>\n" );
document.write( "x = elapsed time in seconds<BR>\n" );
document.write( "y = vertical distance traveled in meters<BR>\n" );
document.write( "We will ignore air resistance because it greatly complicates the problem.\r<BR>\n" );
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document.write( "We are given that the height is 115 meters, so this is the vertical distance needed to hit the ground.<BR>\n" );
document.write( "We'll plug in y = 115 and use this to find x. Keep in mind that x > 0.<BR>\n" );
document.write( "y = 4.9x^2<BR>\n" );
document.write( "4.9x^2 = y<BR>\n" );
document.write( "4.9x^2 = 115<BR>\n" );
document.write( "x^2 = 115/(4.9)<BR>\n" );
document.write( "x = sqrt( 115/(4.9) )<BR>\n" );
document.write( "x = 4.84452141651804<BR>\n" );
document.write( "x = 4.84<BR>\n" );
document.write( "Round the approximate value however you need.\r<BR>\n" );
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document.write( "Answer: <font color=red>Approximately 4.84 seconds</font><BR>\n" );
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