document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1152706>Question 1152706</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An astronaut on the moon throws a baseball upward. The astronaut is 6​ ft, 6 in.​ tall, and the initial velocity of the ball is 30 ft per sec. The height s of the ball in feet is given by the equation s equals  -2.7t^2 + 30t + 6.5​, where t is the number of seconds after the ball was thrown. Complete parts a and b.<BR>\n" );
document.write( "a. After how many seconds is the ball 12 ft above the​ moon's surface? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #774788 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=774788\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> s equals  -2.7t^2 + 30t + 6.5​, where t is the number of seconds after the ball was thrown. Complete parts a and b.<BR>\n" );
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document.write( "a. After how many seconds is the ball 12 ft above the​ moon's surface?<BR>\n" );
document.write( "s(t) = -2.7t^2 + 30t + 6.5 = 12<BR>\n" );
document.write( "2.7t^2 - 30t + 5.5 = 0<BR>\n" );
document.write( "Solve for t<BR>\n" );
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document.write( "The smaller value is ascending.<BR>\n" );
document.write( "The larger is descending.<BR>\n" );
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