+
Website
Pennsylvania State University

Applied Physics: Vibrational Modes of a Circular Membrane (Drums)

For Students 9th - 10th
Site tracks the vibrations of a drum and provides an animated movie.
+
Article
Pennsylvania State University

Applied Physics: Experimental Research on Baseball Bat Vibrations

For Students 9th - 10th
Fun science site that explores the vibrational behavior of a baseball/softball bat. Contains links to mode splitting in wood bats, controlling vibration, measuring the vibration of a baseball/softball bat and more!