A free falling body reached the ground with a speed of 9.8 m / s, from what height did it fall?

To find the height from which a given body should begin its free fall, we will use the law of conservation of energy: Ek = m * V ^ 2/2 = En = m * g * h, whence h = V ^ 2 / 2g.

Variables and constants: V – the speed that the body developed before hitting the ground (V = 9.8 m / s); g – acceleration due to gravity (g ≈ 9.8 m / s2).

Calculation: h = V ^ 2 / 2g = 9.8 ^ 2 / (2 * 9.8) = 4.9 m.

Answer: The original height was 4.9 m.