What kind of work does the gravity force acting on a stone weighing 20 kg do when the stone lies on a 100 m high chip?

h = 100 m.

m = 20 kg.

g = 10 m / s2.

A -?

The mechanical work A of the force F is determined by the formula: A = F * S * cosα, where S is the movement of the body under the action of the force, ∠α is the angle between the direction of action of the force F and the movement of S.

The force of gravity F is always directed vertically downward and is determined by the formula: F = m * g.

The movement of the stone S is a vector that connects the initial and final position of the stone. Since the stone lies on a slope, it is at rest. Its start and end positions are the same, so its movement is S = 0.

If one of the factors is 0, then the whole product is 0.

A = 20 kg * 10 m / s2 * 0m = 0 J.

Answer: when a stone lies on a slope, gravity does not perform mechanical work A = 0 J.