Question 908390
Its height s after t seconds is given by the equation s = 80t − 16t^2.
If the shell is designed to explode when it reaches its maximum height, how long after being fired?
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Max occurs when x = -b/(2a) = -80/(2*-16) = 5/2 seconds
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And at what height, will the fireworks appear in the sky?
f(5/2) = 80(5/2) - 16(5/2)^2 = 200 - 20 = 180 ft
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Cheers,
Stan H.
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