From what height does the stone fall if at the end of the fall its speed is 120 m / s?

To determine the height from which the taken stone began its fall, we apply the law of conservation of energy: m * V ^ 2/2 = m * g * h, whence we express: h = V ^ 2 / 2g.

Variables and constants: V – speed at the end of the fall (V = 120 m / s); g – acceleration due to gravity (g ≈ 10 m / s2).

Let’s make a calculation: h = V ^ 2 / 2g = 120 ^ 2 / (2 * 10) = 720 m.

Answer: The taken stone should have started falling from a height of 720 m.