Abstract
The normal modes of a system of two coupled pendulums were determined by using angular displacement data recorded with rotary motion sensors. As the pendulums oscillated, the angular displacements were measured simultaneously and used to construct a covariance matrix describing their correlated motion. Diagonalization of this covariance matrix revealed two independent mode coordinates corresponding to in-phase and out-of-phase oscillations. Projection of the experimental data onto these mode coordinates produced a clear separation of the system’s behaviors, with the in-phase mode dominating the motion.
