Reference: M171
Category: Mechanics
Purpose: Demonstration of resonance.
Description: A large steel bar is pivoted so that is can swing in a vertical plane. 3 small pith balls referred to as (A), (B) and (C) are being driven to oscillate. (A), (B) and (C) are listed in order of increasing length. (A) moves in anti-phase with a small amplitude, (C) moves in-phase with a small amplitude, and (B) moves in quadrature with a large amplitude. The resistance is not that visible unless (B) is loaded with prestik. This will make it resonate more strikingly because increasing the mass diminishes the importance of air resistance.
