you sense that resonance, and feed it back into it to keep it sustaining. With a tuning fork oscillator, the vibration forcing and the feedback are both done via induction, coils act as the bridge ...

Place the rubber mallet and tuning fork on the lectern with the open end of the resonance box facing the audience. Details of the tuning fork can't be seen in a large lecture hall, but the sound can ...

Two identical tuning forks mounted on resonance boxes are struck with rubber mallets to show they have identical tones. A small piece of putty is added to one tuning fork to alter it's frequency. When ...