The branch of science dedicated to its study is called tribology and the classic approximation for one type of it is named for Coulomb and is expressed as the product of a namesake coefficient and the associated normal force.
In cold welding, molecular effects cause counterintuitive empirical results with respect to this phenomenon. In recent years, accounting for the hexagonal structure of graphite has led to a theory of superlubricity for it. The branch of science dedicated to its study is called tribology and the classic approximation for one type of it is named for Coulomb and is expressed as the product of a namesake coefficient and the associated normal force. For 10 points, what is this physical phenomenon often described as kinetic or static, the force opposing motion between objects in contact?
In cold welding, molecular effects cause counterintuitive empirical results with respect to this phenomenon.
{Friction}