OpenStax
Open Stax: Conservation of Energy
In the following tutorial, students will learn about the law of conservation of energy. They will read about some of the many forms of energy. They will understand the definition of efficiency of an energy conversion process as the...
University of Colorado
University of Colorado: Physics 2000: Bose Einstein Condensation: Temperature and Absolute Zero
From the Physics 2000 site, this page exemplifies their usual superb discussion of the concepts of heat, temperature, and absolute zero. Using an entertaining series of cartoon characters, the page gives a very understandable discussion...
Physics4kids
Physics 4 Kids: Heat and Thermal Energy
When scientists originally studied thermodynamics, they were really studying heat and thermal energy. Heat can do anything: move from one area to another, get atoms excited, and even increase energy. Did we say energy? That's what heat...
University of Sydney (Australia)
University of Sydney: Structure and Properties of Materials/thermal Physics
An exhaustive set of "lecture notes" on various topics in thermal physics (including thermal expansion). Explanations are well done and more interesting than most. Includes both a mathematical and conceptual treatment of topics. Humor,...
University of Colorado
University of Colorado: Physics 2000: Temperature and Absolute Zero
Another awesome page from the Physics 2000 site. Entertaining, interactive, educational, understandable. Explains the meaning of temperature and absolute zero. Discusses the temperature scales. Requires Java.
FT Exploring
Ft Exploring: The Second Law of Thermodynamics
Learn about one of the most misunderstood principles of physics, the second law of thermodynamics.