Wave Behaviour: Reflection & Refraction
📋 What it is
Waves bounce off barriers (reflection) and bend when they change speed (refraction).
🗣️ Coach says
Waves do two key things at boundaries. They reflect — bounce off a surface, giving echoes for sound and images for light. And they refract — bend when they pass into a material where they travel at a different speed. Same two behaviours for sound and light.
🧠 Memory hook
Reflection = bounce (echo, mirror) · refraction = bend when speed changes.
😂 Giggle
What did the wavelength say to the frequency?
"When you go up, I go down — we're inversely related!"
😲 Whoa!
An echo is just your own voice reflecting off a distant surface — if it comes back after about 0.1 second, your brain hears it as a separate echo.
✅ Quick check: What is an echo, in terms of wave behaviour?
Say your answer out loud first — then reveal.
A reflection — the sound wave bounces off a surface and returns to your ears.
Echoes are reflected sound waves.
🧪 Try it! (2 minutes)
Shout toward a far wall or hillside and time the echo — that delay is the wave’s round trip.