Chapter 7: Introduction to Work, Energy, and Energy Resources Flashcards
Define basal metabolic rate
the total energy conversion rate of a person at rest
Define chemical energy
the energy in a substance stored in the bonds between atoms and molecules that can be released in a chemical reaction
Define the 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
Define conservative force
a force that does the same work for any given initial and final configuration, regardless of the path followed
Define 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
Define electrical energy
the energy carried by a flow of charge
Define energy
the ability to do work
Define fossil fuels
Oil, natural gas, coal, etc.
Define friction
the force between surfaces that opposes one sliding on the other; friction changes mechanical energy into thermal energy
Define gravitational potential energy
the energy an object has due to its position in a gravitational field
Define horsepower
An older non-SI unit of power, with 1hp = 746 W
Define kilowatt-hour
unit used primarily for electrical energy provided by electric utility companies (KWh)
Define kinetic energy:
the energy an object has by reason of its motion, equal to1/2mv^2for the translational (i.e., non-rotational) motion of an object of massm moving at speedv
Define 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
Define mechanical energy
the sum of kinetic energy and potential energy
Define metabolic rate
the rate at which the body uses food energy to sustain life and to do different activities
Define net work
work done by the net force, or vector sum of all the forces, acting on an object
Define nonconservative force
a force whose work depends on the path followed between the given initial and final configurations
Define nuclear energy
energy released by changes within atomic nuclei, such as the fusion of two light nuclei or the fission of a heavy nucleus
Define potential energy
energy due to position, shape, or configuration
Define the 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 expression1/2kx^2wherex is the distance the spring is compressed or extended andk is the spring constant
Define power
The rate at which work is done
Define radiant energy
the energy carried by electromagnetic waves
Define thermal energy
the energy within an object due to the random motion of its atoms and molecules that accounts for the object’s temperature
