Purpose: To demonstrate resonance in forced vibrations.

Mass on a spring that oscillates free, or damped in a tube of water. The system can also be driven at various frequencies, and the amplitude of the oscillation can be measured.

1. Push the oscillator with your hand and watch the natural undamped oscillation.
2. Place the end of the oscillating rod into the cylinder of water. Push the oscillator and watch the damped oscillator.
3. Drive the oscillator by varying the vibration frequency and observe the greatly enhanced vibration near the resonant frequency. Drive the oscillator at about 187 Hz and observe the resonance.

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