<PRE><B>Question 611153</B>
 A firecracker shoots up from a hill 140 feet high with an initial speed  of  100 feet per second. Using the
 formula {{{ H(t) = -16t^2 + vt + s }}}, approximately  how long will it take the firecracker to hit the ground?
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{{{ H(t) = -16t^2 + vt + s }}}
{{{ H(t) = -16t^2 + 100t + 140 }}}
At impact, h(t) = 0
{{{ H(t) = -16t^2 + 100t + 140 = 0 }}}
{{{ -16t^2 + 100t + 140 = 0 }}}
Solve for t.  Ignore the negative solution.
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