The interplay of energy and motion of coupled pendulums: a high school student exploration

Abstract The experiment of string-coupled pendulums offers high school students a hands-on opportunity to explore fundamental principles of physics while developing critical skills. In this experiment, students investigate how an oscillating pendulum transfers kinetic energy to a stationary one, resulting in a cyclical exchange marked by role reversals. The motion of the coupled pendulum is studied using a simple smartphone equipped with free software. Pendulums of equal length and point-mass are arranged in three different configurations: pendulum on a fixed rod, pendulum on a string, and string-coupled pendulum. These configurations not only exhibit varying time periods but also significantly different amplitude decay patterns. Despite inevitable energy dissipation due to frictional losses and air resistance, the oscillations exhibited by the coupled pendulums clearly demonstrate the interplay between synchronization and energy transfer. This initial hands-on investigation serves as a springboard for a more comprehensive exploration of the captivating energy transfer mechanisms and dynamical characteristics inherent to string-coupled pendulums.