Answer:
The ballast bag hits the ground after 6 seconds.
Explanation:
Suppose there was a small typing mistake.
The height of the ball, after t seconds, is given by the following equation:

After how many seconds t does the ballast bag hit the ground.
This is t for which f(t) = 0. So






Time is a positive measure, so

The ballast bag hits the ground after 6 seconds.