Step-by-step explanation:
It is given that,
The stone reaches the water surface is 3 seconds. Let d is the distance covered by the by the stone before hitting the water. Initial speed of the stone, u = 0
Using second equation of motion to find the distance covered.

Here, a = g


d = 44.1 meters
So, the stone will cover a distance of 44.1 meters before hitting the water. Hence, this is the required solution.