Answer:
7 seconds.
Step-by-step explanation:
We have been given that the height of a flare fired from the deck of a ship in distress can be modeled by
, where h is the height of the flare above water and t is the time in seconds.
The ball will hit the ground, when height will be 0 meters, so we will equate
to find the time when ball will hit the ground as:

Using quadratic formula, we will get:







Since time cannot be negative, therefore, it will take 7 seconds for the flare to hit the ground.