I sense this belongs under a more general article about friction, to consider at least atmospheric friction, and perhaps initial resistance (e.g., corrosion that breaks free). Alternatively, should this article be retitled "friction" rather than "sliding friction" and have special cases under it? Howard C. Berkowitz 17:33, 2 June 2009 (UTC)
RE: section, Important facts about sliding friction
See: A new look at friction. By Physics Today on November 23, 2009
- Excerpt: We learn in introductory physics classes that the friction force is the product of a friction coefficient and the force normal to the interface. That relationship, embodied in the first of Guillaume Amontons's two laws of friction, has been superseded over the past 50 years by the recognition that the lateral friction or retention force is, in fact, proportional to the true contact area (see Physics Today, September 1998, page 22). Amontons's law turns out to be a special but common case in which the contact area scales linearly with the normal force. In new measurements of liquid drops on surfaces, Rafael Tadmor and colleagues at Lamar University in Beaumont, Texas, observe the opposite behavior: a lowered lateral force despite a larger normal force and an increased contact area…..