A body weighing m = 85kg, falls from a height of h = 70m. What is the speed of this body

A body weighing m = 85kg, falls from a height of h = 70m. What is the speed of this body in the instant before it lands on the ground?

Problem data: m (mass of the falling body) = 85 kg; h (fall height) = 70 m.

Constants: g (acceleration due to gravity) ≈ 10 m / s2.

1 way) Formula of the distance traveled: S = h = (Vk ^ 2 – Vn ^ 2) / 2a = (Vk2 – 0) / 2g, whence we express: Vk = √ (2g * h) = √ (2 * 10 * 70 ) = 37.42 m / s.

Method 2) The law of conservation of energy: Ek = Ep and m * Vk ^ 2/2 = m * g * h, whence Vk = √ (2g * h) = 37.42 m / s.

Answer: An instant before landing, the falling body reached a speed of 37.42 m / s.