PURPOSE: To demonstrate resonance and normal modes.
DESCRIPTION: After starting one of the pendula into motion in the plane of the picture, the motion couples back and forth between the two physical pendula at a rate determined by the spring constant and its location. Coupling can be varied by sliding the spring clamps along the pendula shafts. Normal modes can be nicely demonstrated.
REFERENCES: (PIRA 3A70.27) See Demonstration Reference File for derivation of the equations.
EQUIPMENT: Mounted spring-coupled physical pendula.
SETUP TIME: None.
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