Rolling resistance

Rolling resistance, also called rolling friction and rolling drag is a force of resistance that slows down a rolling motion of one body against another. In other words, it is a force that opposes thetendency of one body to roll against each other.

Important facts about rolling friction

• For rolling resistance to operate, it is not necessary that the two bodies be rolling against each other. In fact, rolling resistance operates even when two bodies are sliding against each other. However, this is negligible compared to the (kinetic) sliding friction acting between the bodies, so is usually ignored.
• Rolling friction operates primarily because of deformations at a microscopic level between the surfaces of contact.
• The amount of rolling friction between two bodies depends on a number of complicated factors, including the nature of the surfaces in contact, the normal force between the two surfaces, and the overall geometry of the bodies.