The height of the object that drops from 144 feet was given by the function
h(t) = -16t^2 + 144
We now set this equation equal to zero because the height of the ground is zero:
0 = -16t^2 + 144
16t^2 = 144
t^2 = 144/16
Taking the square root of both sides, we get the time t the object will hit the ground:
t^2 = 9
t = 3 seconds
Therefore, the answer is 3 seconds.