Experiment of The Month

Pendulum Traveling Wave

Rachel Macey is a MU music major currently doing her student teaching at Kissel Hill Elementary in Warwick School District with music teacher Todd Fulginiti. She built the coupled pendulums shown at the right to demonstrate traveling waves to her students.

The unlike the previous experiment of the month, these pendulums are all the same length. In this demonstration, the black support remains fixed. The pendulums are coupled together with paperclips, visible near the top of each pair of strings.

In order to see a wave traveling, it helps to have the bobs settle down quickly after the wave passes. The highly damped tennis ball bobs serve well for this purpose.

Below are shown a sequence of images, with Ms. Macey starting the right-most pendulum, and the progression of the wave towards the left

Hand Start

start start
middle middle
end end

Students liked the simplicity and the surprising motion.

Ms. Macey also showed some standing wave patterns on a Chladni plate, as in the pictures below