Terms
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.
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
