From what height did the body fall if its speed near the ground turned out to be equal to 20 m / s, disregard air resistance?

Given:

v = 20 meters per second – the speed of the body near the ground at the moment of its fall from a certain height;

g = 10 meters per second squared – the acceleration of gravity.

It is required to determine h (meter) – from what height the body should fall.

Since the problem statement is not specified, the energy losses associated with the force of air resistance will not be taken into account. Then, according to the law of conservation of energy:

Ekinetic (at the moment of falling) = Epotential (at height h);

m * v ^ 2/2 = m * g * h, where m is body weight;

v ^ 2/2 = g * h;

h = v ^ 2 / (2 * g) = 20 ^ 2 / (2 * 10) = 400/20 = 40/2 = 20 meters.

Answer: the body fell from a height of 20 meters.