  The microscopic origin of friction is an important topic in science and
technology. To date, noteworthy aspects of it remain unsolved. In an effort to
shed some light on the possible mechanisms that could give rise to the
macroscopic emergence of friction, a simple 1Dd system of two particles is
considered, one of them free but moving with an initial velocity, and the other
confined by a harmonic potential. The two particles interact via a repulsive
Gaussian potential. While it represents in a straightforward manner a tip
substrate system in the real world, no analytical solutions can be found for
its motion. Because of the interaction, the free particle (tip) may overcome
the bound particle (substrate) losing part of its kinetic energy. We solve the
Newton's equations of the two particles numerically and calculate the net
exchange of energy in the asymptotic state in terms of the relevant parameters
of the problem. The effective dissipation that emerges from this simple,
classical model with no ad hoc terms shows, surprisingly, a range of rich,
non-trivial, behavior. We give theoretical reasoning which provides a
satisfactory qualitative description. The essential ingredient of that
reasoning is that the transfer of energy from the incoming particle to the
confined one can be regarded as the source of the emergent dissipation force,
the friction experienced by the incoming particle.
