SOLUTION: If a ball is thrown upwards at 20 ft/sec, the height h after t seconds is given by h = -16t^2 + 20t. 

How many seconds does it take for the ball to reach its maximum h
Algebra ->
Quadratic Equations and Parabolas
-> SOLUTION: If a ball is thrown upwards at 20 ft/sec, the height h after t seconds is given by h = -16t^2 + 20t. 

How many seconds does it take for the ball to reach its maximum h
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Question 455273: If a ball is thrown upwards at 20 ft/sec, the height h after t seconds is given by h = -16t^2 + 20t. How many seconds does it take for the ball to reach its maximum height, and what is this height? Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! If a ball is thrown upwards at 20 ft/sec, the height h after t seconds is given by h = -16t^2 + 20t. How many seconds does it take for the ball to reach its maximum height, and what is this height?
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The max ht is the vertex of the parabola
The line of symmetry is t = -b/2a = -20/-32
t = 5/8 seconds to reach max ht
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h(5/8) = -16*(5/8)^2 + 20*5/8
= -400/64 + 100/8 = 400/8
Max ht = 50 feet
