Work done by friction during a complete inelastic collision

The work done by the Coulomb frictional force has been addressed by several authors, but still persist some open issues. Friction increases the microscopic energy of a system, and the work done by it needs to satisfy the First Law of Thermodynamics. We present an approach that allows a smooth transition between the works calculated within the domains of newtonian mechanics and thermodynamics. This is done for a symmetric complete inelastic collision where it is possible to calculate the work done by friction on each colliding body. Within certain approximation this collision allows to track analytically some of its physical quantities such as momentum and kinetic energy.