document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=192759>Question 192759</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the height h of a toy rocket t seconds after launching is determined by the formula h= -16t^2 + 112t<BR>\n" );
document.write( "a)find the height of the rocket 2.5 seconds after launching<BR>\n" );
document.write( "b) afer how many seconds is the rocket 196 feet above the ground?<BR>\n" );
document.write( "c) when will the rocket hit 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 #144666 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=144666\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the height h of a toy rocket t seconds after launching is determined by the formula h= -16t^2 + 112t<BR>\n" );
document.write( "a)find the height of the rocket 2.5 seconds after launching<BR>\n" );
document.write( "h(2.5) = -16(2.5)^2 + 112(2.5) = 180 ft.<BR>\n" );
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document.write( "b) afer how many seconds is the rocket 196 feet above the ground?<BR>\n" );
document.write( "-16t^2 + 112t = 196<BR>\n" );
document.write( "-16t^2 + 112t - 196 = 0<BR>\n" );
document.write( "t^2 - 7t + 12.25 = 0<BR>\n" );
document.write( "t = [7 +- sqrt(49 - 4*1*+12.25)]/2<BR>\n" );
document.write( "t = [7 +- sqrt(49 - 49)]/2<BR>\n" );
document.write( "t = [7 +- sqrt(0)]/2<BR>\n" );
document.write( "Positive solution:<BR>\n" );
document.write( "t = 7/2 = 3.5 seconds\r<BR>\n" );
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document.write( "c) when will the rocket hit the ground?<BR>\n" );
document.write( "-16t^2 + 112t = 0<BR>\n" );
document.write( "-16t(t - 7) = 0<BR>\n" );
document.write( "t = 0 (means it starts on the ground)<BR>\n" );
document.write( "t = 7 sec (means it ends up on the ground in 7 seconds)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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