document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=570106>Question 570106</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Marco throws a rock straight down from a point 1760 ft above ground, with an initial velocity of 17 ft/sec.<BR>\n" );
document.write( "A. Find an equation that models the height of the rock T seconds after it is launched, and graph the equation.<BR>\n" );
document.write( "B. What is the maximum height of the rock?<BR>\n" );
document.write( "C. How many seconds until it reaches the ground? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #367556 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=367556\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Marco throws a rock straight down from a point 1760 ft above ground, with an initial velocity of 17 ft/sec.<BR>\n" );
document.write( "A. Find an equation that models the height of the rock T seconds after it is launched, and graph the equation.<BR>\n" );
document.write( "h(t) = -32t^2 + 17x + 1760<BR>\n" );
document.write( ".<BR>\n" );
document.write( "B. What is the maximum height of the rock?<BR>\n" );
document.write( "max height is at the vertex<BR>\n" );
document.write( "t = -b/(2a)<BR>\n" );
document.write( "t = -17/(2*(-32)) = 0.265625 secs<BR>\n" );
document.write( "h(0.265625) = -32(0.265625)^2 + 17(0.265625) + 1760<BR>\n" );
document.write( "h(0.265625) = 1762.26 feet<BR>\n" );
document.write( ".<BR>\n" );
document.write( "C. How many seconds until it reaches the ground?<BR>\n" );
document.write( "set h(t) to zero solve for t:<BR>\n" );
document.write( "h(t) = -32t^2 + 17x + 1760<BR>\n" );
document.write( "0 = -32t^2 + 17x + 1760<BR>\n" );
document.write( "applying quadratic equation yields:<BR>\n" );
document.write( "t = {-7.16, 7.69}<BR>\n" );
document.write( "throw out the negative solution leaving<BR>\n" );
document.write( "t = 7.69 secs<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );