Glossary
- basal metabolic rate
- the total energy conversion rate of a person at rest
- chemical energy
- the energy in a substance stored in the bonds between atoms and molecules that can be released in a chemical reaction
- conservation of mechanical energy
- the rule that the sum of the kinetic energies and potential energies remains constant if only conservative forces act on and within a system
- conservative force
- a force that does the same work for any given initial and final configuration, regardless of the path followed
- efficiency
- a measure of the effectiveness of the input of energy to do work; useful energy or work divided by the total input of energy
- electrical energy
- the energy carried by a flow of charge
- energy
- the ability to do work
- fossil fuels
- oil, natural gas, and coal
- friction
- the force between surfaces that opposes one sliding on the other; friction changes mechanical energy into thermal energy
- gravitational potential energy
- the energy an object has due to its position in a gravitational field
- horsepower
- an older non-SI unit of power, with [latex]\text{1 hp } = \text{ 746 W}[/latex]
- joule
- SI unit of work and energy, equal to one newton-meter
- kilowatt-hour
- [latex]\left(\right. \text{kW} \cdot h \left.\right)[/latex] unit used primarily for electrical energy provided by electric utility companies
- kinetic energy
- the energy an object has by reason of its motion, equal to [latex]\frac{1}{2} \text{mv}^{2}[/latex] for the translational (i.e., non-rotational) motion of an object of mass [latex]m[/latex] moving at speed [latex]v[/latex]
- law of conservation of energy
- the general law that total energy is constant in any process; energy may change in form or be transferred from one system to another, but the total remains the same
- mechanical energy
- the sum of kinetic energy and potential energy
- metabolic rate
- the rate at which the body uses food energy to sustain life and to do different activities
- net work
- work done by the net force, or vector sum of all the forces, acting on an object
- nonconservative force
- a force whose work depends on the path followed between the given initial and final configurations
- nuclear energy
- energy released by changes within atomic nuclei, such as the fusion of two light nuclei or the fission of a heavy nucleus
- potential energy
- energy due to position, shape, or configuration
- potential energy of a spring
- the stored energy of a spring as a function of its displacement; when Hooke’s law applies, it is given by the expression [latex]\frac{1}{2} \text{kx}^{2}[/latex] where [latex]x[/latex] is the distance the spring is compressed or extended and [latex]k[/latex] is the spring constant
- power
- the rate at which work is done
- radiant energy
- the energy carried by electromagnetic waves
- renewable forms of energy
- those sources that cannot be used up, such as water, wind, solar, and biomass
- thermal energy
- the energy within an object due to the random motion of its atoms and molecules that accounts for the object’s temperature
- useful work
- work done on an external system
- watt
- (W) SI unit of power, with [latex]\text{1 W } = \text{ 1 J}/\text{s}[/latex]
- work
- the transfer of energy by a force that causes an object to be displaced; the product of the component of the force in the direction of the displacement and the magnitude of the displacement
- work-energy theorem
- the result, based on Newton’s laws, that the net work done on an object is equal to its change in kinetic energy
“Glossary” from College Physics 2e by OpenStax is licensed under a Creative Commons Attribution 4.0 International License.
