Answer:
t = 3 seconds
Step-by-step explanation:
We have the equation, as a function of time, that describes the height of the object that is dropped from the bridge.
The equation is:
[tex]h (t) = 144 - 16t ^ 2[/tex]
Where t is the time in seconds and h is the height in feet.
To know how long it takes the object to fall to the ground we do h (t) = 0 and solve for t.
So:
[tex]0 = 144 - 16t ^ 2\\\\16t ^ 2 = 144\\\\t ^ 2 = \frac{144}{16}\\\\t ^ 2 = 9\\\\t_1 = 3\\t_2 = -3[/tex]
We take the positive solution.
Therefore the object takes 3 seconds to reach the ground
