Two-dimensional pendulum experiments using a spark generator

Student understanding of the superposition of orthogonal harmonic oscillators can be enhanced using a spark generator to record position-versus-time data for small-amplitude pendulum motion in two dimensions. Sophomore-level physics majors in our Waves and Optics class have used this arrangement to analyze the motion of a spherical pendulum and a “Y-suspended” (Blackburn) pendulum that has two effective lengths. We describe the laboratory exercises and show student data and analysis.