document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1099275>Question 1099275</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rock is thrown upward with a velocity of 25 meters per second from the top of a 20 meter high cliff, and it misses the cliff on the way back down. When will the rock be 7 meters from the water, below? Round your answer to two decimal places </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #713705 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=713705\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+h%28t%29+=+-4.9t%5E2+%2B+25t+%2B+20+ ALIGN=MIDDLE  ALT=\"+h%28t%29+=+-4.9t%5E2+%2B+25t+%2B+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "When will the height of the rock be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+h%28t%29+=+7+ ALIGN=MIDDLE  ALT=\"+h%28t%29+=+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+-4.9t%5E2+%2B+25t+%2B+20+ ALIGN=MIDDLE  ALT=\"+7+=+-4.9t%5E2+%2B+25t+%2B+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-4.9t%5E2+%2B+25t+%2B+13+=+0+ ALIGN=MIDDLE  ALT=\"+-4.9t%5E2+%2B+25t+%2B+13+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Use the quadratic formula<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-b+%2B-sqrt%28+b%5E2+-+4%2Aa%2Ac+%29+%29+%2F+%282a%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-b+%2B-sqrt%28+b%5E2+-+4%2Aa%2Ac+%29+%29+%2F+%282a%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+-4.9+ ALIGN=MIDDLE  ALT=\"+a+=+-4.9+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+25+ ALIGN=MIDDLE  ALT=\"+b+=+25+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+13+ ALIGN=MIDDLE  ALT=\"+c+=+13+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-25++%2B-sqrt%28+625+-+4%2A%28-4.9%29%2A13+%29%29+%2F+%282%2A%28-4.9%29+%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-25++%2B-sqrt%28+625+-+4%2A%28-4.9%29%2A13+%29%29+%2F+%282%2A%28-4.9%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-25+%2B-sqrt%28+625+%2B+254.8+%29%29+%2F+%28-9.8%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-25+%2B-sqrt%28+625+%2B+254.8+%29%29+%2F+%28-9.8%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-25+%2B-sqrt%28+879.8+%29%29+%2F+%28-9.8%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-25+%2B-sqrt%28+879.8+%29%29+%2F+%28-9.8%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-25+-+29.661+%29+%2F+%28+-9.8+%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-25+-+29.661+%29+%2F+%28+-9.8+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ( use negative square root to get positive time )<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+54.661%2F9.8+ ALIGN=MIDDLE  ALT=\"+t+=+54.661%2F9.8+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+5.578+ ALIGN=MIDDLE  ALT=\"+t+=+5.578+\"   DISABLED_style= \"max-width:90%; height:auto;\" > sec<BR>\n" );
document.write( "The rock will be 7 meters from the water in 5.58 sec<BR>\n" );
document.write( "------------------------------------------------<BR>\n" );
document.write( "check answer:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+-4.9%2A5.58%5E2+%2B+25%2A5.58+%2B+20+ ALIGN=MIDDLE  ALT=\"+7+=+-4.9%2A5.58%5E2+%2B+25%2A5.58+%2B+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+152.568+%2B+139.5+%2B+20+ ALIGN=MIDDLE  ALT=\"+7+=+152.568+%2B+139.5+%2B+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+6.932+ ALIGN=MIDDLE  ALT=\"+7+=+6.932+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "I think error is due to rounding off.<BR>\n" );
document.write( "check the math & get another opinion if needed\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );