document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=763472>Question 763472</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello! I'm having trouble with a Quadratic Equation word problem, quite frankly, I don't even know where to start. I know the formula, so I'm confident that I can solve it once it's in an equation form, but I just can't seem to get there. The question is:\r<BR>\n" );
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document.write( "Jasmine is a competitive diver. In a dive off an 8m platform, she reaches a maximum height of 8.4m after 0.30 seconds. How long does it take her to reach the water?\r<BR>\n" );
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document.write( "Thank's so much for the help, I really appreciate it!\r<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 #464837 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=464837\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The quadratic equation to use is<BR>\n" );
document.write( "s(t) = -4.9*t^2 +v(0)*t +h(o)<BR>\n" );
document.write( "note that we use 4.9 since we are working in meters, also h(o) = 8 meters<BR>\n" );
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document.write( "now we need to calculate v(o) which is the launch velocity and<BR>\n" );
document.write( "we use rate * time = distance to calculate the rate which is v(0), so<BR>\n" );
document.write( "v(0) * .30 seconds = .4 meters and <BR>\n" );
document.write( "v(0) = .4 / .30 = 1.33 meters/sec<BR>\n" );
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document.write( "now returning to the quadratic above we have<BR>\n" );
document.write( "0 = -4.9*t^2 +1.33*t + 8<BR>\n" );
document.write( "solve for t using the quadratic formula<BR>\n" );
document.write( "t = (-b+sqrt(b^2-4ac)) / 2a = (-1.33 +sqrt(1.33^2 -4*(-4.9)*8)) / 2*-4.9 = -1.15<BR>\n" );
document.write( "t = (-b-sqrt(b^2-4ac)) / 2a = (-1.33 +sqrt(1.33^2 -4*(-4.9)*8)) / 2*-4.9 =  1.42\r<BR>\n" );
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document.write( "therefore she reaches the water in 1.42 seconds<BR>\n" );
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