Potential energy

Potential energy is the energy that bodies in a force field have. There are several types of potential energy.

1. Gravitational potential energy

Bodies in a gravitational field have this type of potential energy, which depends on the altitude they are at.

If we conventionally set the ground level as the reference level, we will say that all bodies on the ground have 0 gravitational potential energy, and a body of mass m located at height h from the reference level (ground) will have the potential energy:

$E_{PG} = m \cdot g \cdot h$

(1)

The unit of gravitational potential energy is 1J, just like any form of energy.

It is no coincidence that the formula for defining kinetic energy is identical to the expression for the mechanical work required to lift a mass body m, from ground level to height h.

Example: a mass body m=1kg sits on the ground and to lift it up h=10m a mechanical work must be done L= 100J. The energy consumed in this mechanical action will be found in a form of energy called gravitational potential energy, which has the value Ep= 100J. This energy is conserved as long as the body remains up there. By falling back to the ground, the energy accumulated in this way is restored.

2. Elastic potential energy

Deformed elastic bodies store this type of energy.