PURPOSE: To demonstrate a linear coupling resonance and normal modes.
DESCRIPTION: Move the bob straight up or down a few inches and release it quickly. It first starts to oscillate vertically, then its energy transfers entirely into rotational motion, then back to pure translation. This motion then repeats. By lifting the mass directly upward and at the same time rotating it (in either direction) before release, the two normal modes of the Wilberforce pendulum can be produced.
REFERENCES: (PIRA 3A70.10) See Demonstration reference File for a number of interesting articles.
EQUIPMENT: Mounted Wilberforce pendulum.
SETUP TIME: None.
Go back to Lecture-Demonstration Home Page.