Chapter 3

in electricity: when an electric charge moves in an electrically conductive substance, such as metal. in heat transfer: the process of heat transfer by the propagation of vibrations of atoms in a solid.

the principle that energy can neither be created or destroyed only changed in form.

the process of heat transfer by molecular motion in fluids as fast molecules mingle with slower molecules, they collide and energy is transferred from the faster molecules to the slower molecules.

a liquid or gas.

when energy is transferred from a warm object to a cooler one by means of infrared radiation, thermal conduction, or convection.

the sum of all kinetic energies possessed by all the particles in a substance.

Einstein’s theory (1905) that mass and energy are different forms of the same thing, that amount of mass and energy may each be expressed in terms of each other; the theory can be used to calculate the energy released when a quantity of matter is converted into energy in a nuclear reaction.

the theory that heat and kinetic energy are different forms of the same thing (energy) and may be converted from one form to another.

electro magnetic waves. in heat transfer, refers specifically to electromagnetic waves in the infrared region of the electromagnetic spectrum. not to be confused with nuclear radiation, which can involve massive particles, such as protons, electrons, and neutrons.

a state when two objects (or an object and environment) are at the same temperature and heat flow between them ceases.

a mechanical process whereby energy is transferred from one object to another by a force pushing through a certain distance.