Verified answer

Answer:

Therefore the final velocity of stone just before touching the ground will be 19.6 m/s.

Explanation:

initial velocity (u) = 0 m/s

Height (h) = 19.6 m

acceleration due to gravity (g) = 9.8 m/s^2

Let the final velocity just before touching the ground be v

We know, v^2 = u^2 + 2gh

or, v^2 = 0 + 2 × 9.8 × 19.6

or, v^2 = 19.6 × 19.6

or, v = 19.6

Thus the velocity of stone just before hitting the ground will be 19.6 metres per second .