Science & Mathematics » Physics » Physics Concept: conservative vs. Non-Conservative Force?

# Physics Concept: conservative vs. Non-Conservative Force?

Briefly explain the concept of a conservative force vs. a non-conservative force.

• A conservative force, is a force whereby which the work done by it, can be tracked by a potential energy quantity.

A potential energy term, will be a function of position/configuration of the system. Based on THE STATE of all components in the system at any given instant, there is a given amount of energy in the form of all types of potential energies. It does not depend on what path the system takes, for these potential energies to have meaning. Potential energy is a state function, in contrast with work as a path function.

In order for a conservative force to be such, the NET WORK done by it on an object, as the object moves in a closed path, returning to its initial position/configuration, must be zero.

A non-conservative force, is one where this isn't the case. If it is more trouble than it is worth to develop the corresponding quantity of potential energy, than likely a force is non-conservative. Either that, or the energy transformation involved with a force, is an irreversible process.

There is a third category of force, which is forces of constraint. These are forces which by definition, do not do work on the object. Usually because they constrain against any motion in the direction they act.

Examples of conservative forces are as follows:
Gravity
Spring forces and other geometries of reversible elasticity
Electrostatics
Buoyancy

Examples of non-conservative forces:
Drag
Sliding friction
Human pushes and pulls

Examples of forces of constraint:
The normal force for a rigid surface
The tension in an inextensible string
Traction
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