A simple set-up for tracking the motion of a single particle in kinetic granular matter

Abstract

We present an undergraduate laboratory activity for observing the collision path of a single particle in a dynamic granular matter system. Experiments use a speaker to provide energy for random collisions among plastic pellets. Coordinates of a moving representative pellet are recorded over time by a digital camera. Analysis of the resulting videos is based on four characteristics: random paths, fractal behavior, dependence between displacement and elapsed time, and velocity distributions. We discuss deviations of the observed particle behavior from Brownian motion.