Spinning Object Stability - Physics Demonstrations - Spinning Object Stability | Physics Undergraduate Labs

Keep a clear zone around the demonstration. Never point the drill toward the audience. Inspect strings and connections before each use.

Purpose

A ring, disc, and rod suspended from strings and spun by a cordless drill each rise from hanging vertically to spinning horizontally. Demonstrates that at sufficient angular velocity, objects rotate about their axis of maximum moment of inertia, minimizing $$E = L^2/2I$$ .

Four objects painted in alternating orange and black on a gray surface: a large ring (lower left), a solid disc with radial wedge pattern (upper center), and two rods (right), each with a string and small metal connector for attaching to a drill chuck

Figure 1: Ring, disc, and rods — objects with different moment-of-inertia distributions, each on a string for attachment to a cordless drill.

Cordless Drill

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Safety Warnings

Warning: Spinning Object Hazard

Purpose