document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1088268>Question 1088268</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is dropped vertically off a 45m building. The function that describes the height of the ball as a function of time is h(t)=-5t^2+45 where height is measured in meters and time in seconds.<BR>\n" );
document.write( "A) calculate the height of the ball after 2 seconds [h(2)]<BR>\n" );
document.write( "B) calculate the time taken for the ball to hit the ground [h(t)=0] </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #702514 by </B><A HREF=/tutors/aboutme.mpl?userid=addingup><B>addingup(3677)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=addingup><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=addingup><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=702514\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A) -5t^2+45 = -5(2)^2+45 = 25 meters<BR>\n" );
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document.write( "B) The ball has to drop 45 meters (the height of the building). <BR>\n" );
document.write( "Gravity: g = 9.8 m/s^2<BR>\n" );
document.write( "y: vertical displacement in meters (45 meters)<BR>\n" );
document.write( "t = sqrt(2gy)/g<BR>\n" );
document.write( "t = sqrt(2gy)/sqrt(g^2) now simplify:<BR>\n" );
document.write( "t = sqrt(2y/g)<BR>\n" );
document.write( "t = sqrt 2(45)/9.8 = 3.03 seconds<BR>\n" );
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