Decagon Charged Pendula and Beyond

Abstract

We consider a set of n identical charged pendulums and hang them from a common pivot. The electrostatic repulsive charge-charge interaction between the pairs repels the pendulums apart. The weight and the tension of the pendulums balance the coulombian repulsion stabilizing the setup to final static equilibrium. The final configuration is a horizontal n-gon inscribed in a circle of radius, R. It is the objective of our investigation to measure R as a function of mass, length and charge, {m,?,q}, of the pendulum for a number of pendulums, n, within the range of 2?n