NONLINEAR DYNAMICS OF A SINUSOIDALLY DRIVEN PENDULUM IN A REPULSIVE MAGNETIC-FIELD

The dynamics of a sinusoidally driven pendulum in a repulsive magnetic field is investigated theoretically and experimentally. The experimen tal data are acquired using a shaft encoder interfaced to a PC which m easures the angular displacement of the pendulum as a function of time , Both the theoretical simulations and the experimental measurements e xhibit regions of periodic and chaotic behavior, depending on the syst em parameters. Amplitude jumps, hysteresis, and bistable states are al so observed. The simplicity of the apparatus makes this experiment sui table for an advanced undergraduate laboratory. (C) 1997 American Asso ciation of Physics Teachers.