ANSWER
the object will hit the ground at 4.793 seonds
Explanation
Given the function below
To find the value of t in seconds, let s(t) = 0
The new equation becomes
The quadratic function can be solved using the general quadratic formula
From the equation above,
Let a = -16, b = 60, and c = 80
Hence, the object will hit the ground at 4.793 seonds