Driven Mechanical Resonance Concept

Demonstrations in Driven Mechanical Resonance

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

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 …
Flexible metal strip loop mounted vertically on a clear cylindrical base with driver mechanism, connected to a Daedalon audio driver box displaying 22.3 Hz. The loop is visibly distorted into a non-circular shape by the 3rd harmonic standing wave.

Resonance in a Loop

Demonstrates resonance and harmonics of standing waves on a vibrating loop. Students observe that only specific discrete frequencies produce stable standing wave patterns, illustrating boundary conditions and wavelength quantization in …
Seven dark blue metal leaf springs of decreasing height with brass block caps, mounted on a brass rail on a red wooden base, with motor and pulley assembly at right end

Leaf Springs Resonance

As the motor speed scans from low to high frequency, successively shorter leaf springs resonate one by one, oscillating violently when the driving frequency matches their natural frequency. Students see …
Top: Ratiotrol speed control, driving motor, and balance wheel with spiral spring on a demo bench. Bottom: shadow projection of the balance wheel on a screen showing the oscillation clearly

Driven Spiral Oscillator

A motor-driven spiral spring oscillator demonstrates resonance by sweeping the driving frequency through the system's natural frequency. Students observe the dramatic amplitude peak at resonance, the phase shift from in-phase …