Terms
Energy

The ability to do work.
Work

A force applied over a distance. For formulae, 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.
Kinetic Energy

The energy of motion.
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.
Formulae
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.
