
Conservative force
Any force which conserves mechanical energy, as opposed to a nonconservative force. See statement of conservation of mechanical energy.

Conservative System
A system in which energy is conserved.

Energy
The ability to do work.

Kinetic Energy
The energy of motion.

Nonconservative Force
Any force which does not conserve mechanical energy, as opposed to a conservative force.

Path independence
Property of conservative forces which states that the work done on any path between two given points is the same.

Potential energy
The energy of configuration of a conservative system. For formulae, see Definition of potential energy, gravitational potential energy, and Definition of potential energy given a positiondependent force.

Total mechanical energy
The sum of the kinetic and potential energy of a conservative system. See definition of total mechanical energy.

Work
A force applied over a distance. For formulas, see work done by a constant force parallel to displacement and work done by any constant force, and work done by a positiondependent force.

Joule
The units of work, equivalent to a Newtonmeter. Also units of energy.

Power
Work done per unit time. For formulas, see Formula for average power, Definition of instantaneous power, and formula for instantaneous power.

Watt
Unit of power; equal to joule/second.
Terms
Formulas
Work done by a constant force parallel to displacement  W = Fx 
Work done by any constant force  W = Fx cosθ 
WorkEnergy Theorem  W = ΔK 
Formula for average power  = 
Definition of instantaneous power  P = 
Formula for instantaneous power  P = Fv cosθ 
Work done by a positiondependent force  W = F(x)dx force. 
Definition of potential energy.  ΔU =  W 
Gravitational potential energy.  U_{G} = mgh 
Statement of conservation of mechanical energy.  Δ(U+K) = 0 
Definition of total mechanical energy.  U + K = E 
Definition of potential energy given a positiondependent force.  ΔU =  F(x)dx 