Resonant Bowling Ball Pendulum - Physics Demonstrations - Resonant Bowling Ball Pendulum | Physics Undergraduate Labs

The bowling ball represents a substantial swinging mass with significant momentum at large amplitudes. Ensure all students and equipment are clear of the entire swing path before beginning. Do not attempt to stop the ball by grabbing it—allow it to naturally damp down.

Purpose

A bowling ball on a 5.4 m cable forms a pendulum with a ~4.7 s period. Gentle pushes on alternating sides every ~2.3 s (matching the half-period) build large-amplitude swings through resonance. Pushing at the wrong frequency produces only small jiggling, dramatically showing that energy transfer requires frequency matching.

Black bowling ball suspended by cable and hardware, with a hand giving it a gentle push; white floor and yellow wall visible in background

Figure 1: The bowling ball pendulum hangs from a 5.4 m cable. Gentle pushes on alternating sides at the half-period (~2.3 s) drive it into resonance.

Bowling Ball with Hook Attachment

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Safety Warnings

Warning: Swinging Mass Hazard

Purpose