<PRE><B>Question 63915</B>
A toy rocket is fired from a building. Its height at time t is given by the equation: h(t) = -16t^2 + 396t + 100. When will it land on the ground below the bulding and what is its height after 10 seconds ?
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When it hits the ground the height will be zero.
Solve h(t)= -16t^2+396t+100 = 0
t=[-396+-sqrt(396^2-4*-16*100)/(-32)
t=-0.25 sec or t=25 sec
Answer: t=25 sec
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Height after 10 seconds = h(10)=2460 ft.
Cheers,
Stan H.
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