We report on the design and construction of a series of coupled pendula to demonstrate various aspects of wave motion, such as normal modes, standing waves, a dispersion relation, and evanescence waves. The experiment can help undergraduate students obtain a better understanding of the properties of wave motion.

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The PhETTM Project at the University of Colorodo, Boulder, has a large repository of educationally oriented simulations, including one for normal modes: <http://phet.colorado.edu/en/simulation/normal-modes>.
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