With what speed should the body be lifted up so that it flew up to a height of 120 m?

Initial data: h (the height to which the body should fly up) = 120 m.

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

The speed with which it is necessary to throw the body up, we define using the law of conservation of energy: En = m * g * h = m * V ^ 2/2 = Ek, whence V ^ 2 = 2 * g * h and V = √ (2 * g * h).

Calculation: V = √ (2 * 10 * 120) = √2400 ≈ 49 m / s.

Answer: The body must be thrown upwards at a speed of 49 m / s.