91影视

The force and the potential energy of the particle are both related if the force is a conservative force.

If the force is conservative it can be defined as negative of the vector gradient of the potential energy:

$\mathit{F}\mathbf{=}\mathbf{-}\mathbf{鈭�}\mathit{U}$

If the force is conservative (energy of the particle is conserved under the application of the force if the particle moves in a closed loop or, the change in energy of the particle is zero when it returns to its original position under the application of the force), it can be defined as negative of the vector gradient of the potential energy:

$F=-鈭�U$

So, the force and the potential energy of the particle are both related if the force is a conservative force. If we know the potential energy, we know the force and if we know the force, we know the potential energy (only upto a constant but it does not matter because zero of the potential energy can be defined anywhere). And in physics, we often work with conservative forces, for example: gravitational force, electromagnetic force, spring force etc.

So, the two are analogous and therefore the term interaction is used to cover both of them. For example, while working with gravity, whether we say "the gravitational force acting on a particle at a particular point in space is this much" or "the gravitational potential energy of the particle at that particular point in space is that much", both the statements describe the same phenomenon.