Question

A projectile is thrown upward so that its distance above the ground after

t seconds is h = -16t2 + 608t.
After how many seconds does it reach its maximum height? (5 points)

Answer 1

Answer: 19 seconds

Explanation:

The maximum height of this parabola will be when the slope of the line hits zero. Take the first derivative and set it to 0, solve for t.

h = -16t2 + 608t

h' = -32t + 608

32t = 608

t = 19 sec

[The height at 19 seconds is h = -16(19)^2 + 608(19) = 5776 feet