Determine the mass of a body that at a height of 5 m had a potential energy equal to 120 J.

Given: h (body height relative to the zero level) = 5 m; En (potential energy possessed by the body) = 120 J.

Constants: g (acceleration due to gravity) = 9.81 N / kg ≈ 10 N / kg.

The mass of the body is determined from the formula for calculating the potential energy: En = m * g * h, whence m = En / (g * h).

Let’s make the calculation: m = 120 / (10 * 5) = 2.4 kg.

Answer: Body weight is 2.4 kilograms.