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Terms and Formulae


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 position-dependent force.
Joule  -  The units of work, equivalent to a Newton-meter. 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.


Work done by a constant force parallel to displacement W = Fx
Work done by any constant force W = Fx cosθ
Work-Energy Theorem W = ΔK
Formula for average power =
Definition of instantaneous power P =
Formula for instantaneous power P = Fv cosθ
Work done by a position-dependent force W = F(x)dx force.