Task: Text Categorization
Input (English): This phenomenon originates from asperities which can be modeled with the Archard equation. On an atomic scale, this is described by the Tomlinson model, including a namesake parameter that, when greater than one, results in the stick-slip variety of this phenomenon. Reye hypothesized that this is proportional to volume of wear debris. Amontons' second law states that it is independent of the area of the contact surface. It is equal to the normal force times mu, its namesake coefficient, which has static and kinetic varieties. For ten points, name this force that acts opposite motion.
Output (English): Science