A body weighing 5 kg. falls freely down. Determine the speed of the body when it hits the surface of the Earth

A body weighing 5 kg. falls freely down. Determine the speed of the body when it hits the surface of the Earth, if at the initial moment it had a potential energy of 490J.

Given:

m = 5 kilograms is the mass of a freely falling body;

Epotential = 490 Joules – potential energy of the body at the initial moment of time.

It is required to determine v (m / s) – the speed of the body at the moment of impact on the ground.

According to the law of conservation of energy, all the potential energy possessed by the body at the initial moment of time will go into kinetic at the moment of impact on the ground:

Epotential = Ekinetic;

Epotential = m * v ^ 2/2

v = (2 * Epotential / m) ^ 0.5 = (2 * 490/5) ^ 0.5 = (980/5) ^ 0.5 = 196 ^ 0.5 = 14 m / s.

Answer: at the moment of hitting the ground, the body will have a speed equal to 14 meters per second.