Answer:
3.1 seconds
Explanation:
The diver will hit the water when the height is zero.
0 = -5t^2 +11t +13
Using the quadratic formula, we find the solutions to be ...
t = (-11 ±√(11^2 -4(-5)(13)))/(2(-5)) = (-11 ±√381)/-10
The positive solution is
t = 1.1 +√3.81 ≈ 3.1 . . . seconds
The diver will hit the water after 3.1 seconds.