Damped Driven Oscillator

A mass is mounted on a spring, and the mass is submerged in a large beaker of water. With no driving force, oscillations are damped out quickly. The oscillations can be driven at a tunable frequency. Observe:

• Large amplitude motion at resonance. (It's a good idea to have a piece of rubber or something beneath the mass to avoid shattering the beaker).
• Change of phase for motion above and below resonance.

Click on the image to see a movie of this demo.