World's Fastest Simplest Electric Train

Optimizes parameters of the world's simplest electric train for maximum speed.

The so-called world's simplest electric train is comprised of a AA battery with a small electroplated permanent magnet at each end. Almost miraculously, it self-propels when placed inside a coil of bare wire. Quite inexpensive and easy to construct, this homopolar motor offers many lessons to physics and engineering students. This script explores the fundamental physical quantities governing its operation and provides an illustrative nonlinear constrained optimzation to explore how one might construct the world's fastest simplest electric train. This tutorial may provide the student a sense of computation applied to a toy engineering problem.