  Motion of particles (bodies) in presence of random effects can be considered
stochastic process. However, application of widely known stochastic processes
used for description of particle motion is reduced to relatively small class of
particle transport phenomena. Stochastic state-transition-change (STC) process
is suitable for description of many systems. In this paper it is shown under
which assumptions formulae of time resolved velocity spectrometry can be
derived with the help of STC process. It opens up new possibilities of unified
description of particles moving in a force field in presence of random effects.
It extends possibilities of applications of theory of stochastic processes in
physics.
