  The response of mechanical systems composed of springs and dashpots to a step
input is of eminent interest in the applications. If the system is formed by
linear elements, then its response is governed by a system of linear ordinary
differential equations, and the mathematical method of choice for the analysis
of the response of such systems is the classical theory of distributions.
However, if the system contains nonlinear elements, then the classical theory
of distributions is of no use, since it is strictly limited to the linear
setting. Consequently, a question arises whether it is even possible or
reasonable to study the response of nonlinear systems to step inputs. The
answer is positive. A mathematical theory that can handle the challenge is the
so-called Colombeau algebra. Building on the abstract result by (Pr\r{u}\v{s}a
& Rajagopal 2016, Int. J. Non-Linear Mech) we show how to use the theory in the
analysis of response of a simple nonlinear mass--spring--dashpot system.
