document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1164239>Question 1164239</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rock is thrown upward with a velocity of 21 meters per second from the top of a 48 meter high cliff, and it misses the cliff on the way back down.  When will the rock be 7 meters from ground level?  Round your answer to two decimal places.<BR>\n" );
document.write( " using 9.8 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #788523 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=788523\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rock is thrown upward with a velocity of 21 meters per second from the top of a 48 meter high cliff, and it misses the cliff on the way back down.  When will the rock be 7 meters from ground level?  Round your answer to two decimal places.<BR>\n" );
document.write( " using 9.8<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "Its vertical position is<BR>\n" );
document.write( "h(t) = -4.9t^2 + 21t + 48<BR>\n" );
document.write( "-4.9t^2 + 21t + 48 = 7<BR>\n" );
document.write( "Solve for t </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );