Question 514342
a projectile is fired upward with a velocity of 860 ft/sec from a height of 7ft above the ground.Determine the function of the hightof the projectile t after it is release. How long will it take to reach a height of 100ft up. How long will it it stay in the air.
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Height formula wrt time in seconds
h(t) = -16t^2+vo(t)+s(o)
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h(t) = -16t^2 + 860t + 7
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Time for height = 100 ft.
-16t^2+860t+7 = 100
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-16t^2+860t-93 = 0
t = 0.1084 seconds on the way up  or t = 53.64 seconds on the way down
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How long will it it stay in the air.
Solve -16t^2 + 860t + 7 = 0
t = 53.76 seconds
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Cheers,
Stan H.
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