How is temperature defined in physical terms?

Temperature is defined in physical terms as a measure of the average kinetic energy of the particles in a substance. When the temperature of an object increases, it indicates that the particles are moving more rapidly on average, which corresponds to greater kinetic energy. This relationship is fundamental to understanding thermodynamics and how heat transfers occur between bodies at different temperatures.

As the temperature goes up, the increased kinetic energy results in more vigorous movement among particles, leading to changes in physical state and the ability of materials to conduct heat. This understanding of temperature as directly related to kinetic energy helps explain various natural phenomena, including thermal expansion and phase changes.