<PRE><B>Question 313615</B>
If a ball is thrown vertically upward from a height of 5 ft, with an initial velocity of 96 ft/s, its height h after t seconds is given by h = -16t^2 + 96t + 5. How long does it take the ball to pass through a height of 120 ft on the way back down to the ground?
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h = -16t^2 + 96t + 5
120 = -16t^2 + 96t + 5 solve for t
-16t^2 + 96t + 5 = 120
-16t^2 + 96t + -115 = 0
*[invoke solve_quadratic_equation -16,96,-115]
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t = 1.65 seconds going up
t = 4.346 seconds falling
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