Rolling friction in a 3D printed stringless pendulum

Abstract

The motion of a billiard ball rolling on a 3D printed stringless pendulum was studied by video analysis. This allows for the measurement of the eigenfrequency as well as the coefficients of viscous drag and rolling friction. The stringless pendulum consisted of two circle sectors with variable distance, such that friction coefficients could be determined as a function of rolling radius. Rolling resistance decreases with increasing rolling radius, but does not follow a simple power law; instead the data suggest an exponential dependence.