Mass On Spring - Hand Held

Purpose

To demonstrate the concept of resonance and the idea of phase shift at resonance.◙

Equipment

Mass on spring, hand.

Images

Description

The mass on the spring has a natural frequency, which can be demonstrated by simply holding one end of the spring a rest and allowing the mass to oscillate freely. Demonstrate resonance as follows: (1) With the mass hanging at rest, move your hand very slowly up and down. The mass follows your hand, showing that the mass and the driving force stay in phase for driving frequencies far below the natural frequency of the oscillator. (2) With the mass hanging at rest, move your hand very rapidly up and down. The mass moves opposite to your hand, showing that the mass and the driving force stay out

References

Shirin Haque-Copilah, Extremely simple demonstration of forced oscillation, AJP 64, 507-508 (1996).