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 s liding the spring clamps along the pendula shafts, by changing masses, and by changing the positions of the masses. Normal modes can be nicely demonstrated.
SUGGESTIONS:
EQUIPMENT: Mounted spring-coupled physical pendula.
SETUP TIME: None.