Why does a bridge shake and a flute sing?
Part 2 — every object has its own way of vibrating. Pushing it at just the right rhythm makes it vibrate hugely; and the way a source vibrates decides how loud, how high and how rich its sound is.
In this lesson you will
- Distinguish natural, damped and forced vibrations with one example each
- Explain resonance using two pendulums on a common string, with useful and harmful examples
- Relate loudness to amplitude, pitch to frequency and quality to waveform
- Name the decibel and suggest ways to reduce noise pollution
| Everyday event | Idea |
|---|---|
| A swing pushed in step goes higher and higher | Resonance |
| A struck bell slowly dies away | Damped vibration |
| A tabla and a whistle sound different | Quality |
| A drum hit harder sounds louder | Loudness and amplitude |