Rolling Disk Set

DCS Code: 1Q10.35 Last Updated: March 27, 2026
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Purpose

Demonstrates that objects with identical moments of inertia accelerate identically down a ramp, regardless of differences in mass and radius. Challenges the common misconception that heavier objects roll faster.

Three objects on a gray surface: large wooden disk with CENCO label (left), medium translucent acrylic disk (center), and small brass cylinder lying on its side (right)
Figure 1: The wooden disk (large, light), acrylic "raindrop" disk (medium), and brass cylinder (small, heavy) have different masses and radii but identical moments of inertia.
Demo Apparatus