Answer:
14 m/s
Explanation:
The motion of the stone is a free fall motion, so an accelerated motion with constant acceleration g = 9.8 m/s^2 towards the ground. So, we can use the following SUVAT equation:
where
v is the final speed of the stone as it reaches the water
u = 0 is the initial speed
g = 9.8 m/s^2 is the acceleration
h = 10 m is the distance covered by the stone
Solving for v, we find