Various simulations of physical systems found in Physics Olympiad questions.

pitfall - rod connects two masses, one is constrained to a horizontal line (USAPhO 2019 B3)
rods - two rods connect three masses (EuPhO 2018 T1)
rope - resonances of a hanging rope (EuPhO 2017 T1)
wall - motion of a charged particle in a plane electromagnetic wave
gradient index - quadratic variation of index of refraction results in convergence of wavefronts to a common focal point (EuPhO 2023 T1)
boom - supersonic plane flies in variable index of refraction atmosphere (USAPhO 2025 B2)