Answer:
Step-by-step explanation:
Note that the given height equation, which is a quadratic) has a graph that opens downward. Borrowing the quadratic formula, we find the roots of this equation, that is, the t values at which h(t) = 0:
The coefficients of this equation are a = -16, b = 80 and c = 0.
We need to find the roots of this quadratic. By the quadratic formula,
-(80) ±√(80² - 4(-16)(0) ) -80 ± 0
t = ------------------------------------- = ----------------- = -5/2 and -5/2 (seconds).
2(-16) -32
The initial height is 0 at t = 0 seconds and the final height 0 at 5/2 seconds.
