PURPOSE: To create waves in a very dramatic way using a series of carefully adjusted pendula of various lengths.

DESCRIPTION: This is a commercial version of our demonstration G1-82: Pendulum Waves. After the pendula are started into oscillation in phase, they pass through a series of various standing wave and traveling wave patterns, finally returning to their initial mode, in which they were all in phase.

SUGGESTIONS: Practice starting the pendula in unison a few times before performing the demonstration in front of the class.

REFERENCES: (PIRA 3B10.75) See Demonstration Reference File for more information. The web site Pendulum Waves: A Lesson in Aliasing, by James Flaten and Kevin Parendo contains interesting computer simulations of similar apparatus.

We have produced videos of the action in several formats:

• 12.4 megabyte mpeg Video (excellent quality)
• 2.3 megabyte Quicktime Video (poor quality)
• 1.1 megabyte Real Media Video (good quality)
• 2.2 megabyte Windows Media Video (excellent quality)

EQUIPMENT: As photographed.

SETUP TIME: None.