Introduction to Tribology (Friction, Wear & Lubrication): What are sliding and rolling friction?

This video presents the basic definition of Tribology which includes friction, wear and lubrication. Several examples are provided. There is also a live demonstration of how to measure the coefficient of friction experimentally. Tribology is defined as "the science and technology of interacting surfaces in relative motion and of related subjects and practices". The word mentioned at 2 minute "Tribos" (Greek word) means path or worn away. "Tribo" is derived from "Tribos" and in English it means "to rub". There are two types of friction - sliding friction and rolling friction. Sliding friction tends to be much larger than the rolling friction. This video provides answer as to why this is so using the science (physics) of friction. In the live experiment, you can see how coefficient of friction changes when we change the nature of the surface, for example, by introducing a rubber band on one of the surfaces. Please write your comments and questions below in the comment section. Also, do like this video and subscribe to this channel. Please help spread the knowledge by forwarding this video to people you know in the areas of science and engineering.