Questions and Answers: Physics
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 position-dependent 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 position-dependent force.
Joule - The units of work, equivalent to a Newton-meter. 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 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. 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
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 position-dependent 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 position-dependent force.
Joule - The units of work, equivalent to a Newton-meter. 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 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. 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