SOLUTION: The height h of an object t seconds after it is dropped off a building is given by the equation h=-16t^2+144. How many seconds after the rock is dropped will it hit the ground?

Question 138370: The height h of an object t seconds after it is dropped off a building is given by the equation h=-16t^2+144. How many seconds after the rock is dropped will it hit the ground?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The height h of an object t seconds after it is dropped off a building is given by the equation h=-16t^2+144. How many seconds after the rock is dropped will it hit the ground?
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When it hits the ground its height is zero.
-16t^2+144 = 0
16t^2 = 144
t^2 = 9
t = 3 seconds
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Cheers,
Stan H.
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