kinetic theory

noun

: either of two theories in physics based on the fact that the minute particles of a substance are in vigorous motion:

a

: a theory that the temperature of a substance increases with an increase in either the average kinetic energy of the particles or the average potential energy of separation (as in fusion) of the particles or in both when heat is added

called also kinetic theory of heat

b

: a theory that the particles of a gas move in straight lines with high average velocity, continually encounter one another and thus change their individual velocities and directions, and cause pressure by their impact against the walls of a container

called also kinetic theory of gases

Word History

First Known Use

1864, in the meaning defined above

Kids Definition

kinetic theory

noun

: a theory that states that all matter is composed of particles in motion and that the rate of motion varies directly with the temperature