18.2 Absolute Zero

Temperature Measures Average Kinetic Energy

The hotness of a material is related to the average kinetic energy of the submicroscopic particles within that material. In general, the hotter the material, the greater the average kinetic energy of its particles. We say "average" kinetic energy because the particles are all moving at different speeds--some fast some slow. Duration: 1:40.

Thermometers Measure Temperature

Temperature is best judged using some external reference, such as the expansion or contraction of a liquid. Two temperature scales, the Celsius and Fahrenheit, are demonstrated. Duration: 6:06

The Tailor of Celsius!

The story of the tailor of Celsius is used to illustrate the need for the Kelvin temperature scale. This absolute scale is then compared with the Celsius and Fahrenheit scales. Duration: 8:16