Wave Interference & Resonance
📋 What it is
Overlapping waves add up or cancel (interference); matching a natural frequency makes resonance.
🗣️ Coach says
When two waves meet they combine: peaks-on-peaks reinforce (louder/brighter), peak-on-trough cancels (quieter/darker) — that’s interference. And every object has a natural frequency; push it at exactly that rate and it vibrates hugely — resonance, like a swing pushed at just the right moment.
🧠 Memory hook
Waves overlap → add (louder) or cancel (quieter) = interference. Match the natural rate → resonance.
😂 Giggle
Why was the electromagnetic spectrum so diverse?
It had everything from radio waves to gamma rays — talk about range!
😲 Whoa!
Noise-cancelling headphones create a sound wave that is the exact "opposite" of the noise — the two cancel, and the roar goes quiet.
✅ Quick check: How do noise-cancelling headphones make noise disappear?
Say your answer out loud first — then reveal.
They produce an inverted wave that cancels the incoming noise wave (destructive interference).
Opposite waves cancel — destructive interference silences the sound.
🧪 Try it! (2 minutes)
Push a friend on a swing at just the right rhythm — small pushes build a big swing: resonance.