Potential Energy Relation With Force

The potential energy of a system increases if work is done:

1.	by the system against a conservative force
2.	by the system against a non-conservative force
3.	upon the system by a conservative force
4.	upon the system by a non-conservative force

The potential energy of a particle in a force field is where and are positive constants and is the distance of the particle from the centre of the field. For stable equilibrium, the distance of the particle is:

1.		2.
3.		4.