Send straight ripples across a tank and you can make them do three things: bounce off a barrier, bend as they cross into shallower water, and fan out as they squeeze through a gap. Every wave, of every kind, can do all three.
Waves reflect when they bounce off a barrier, with the angle of incidence equal to the angle of reflection. They refract when they change speed crossing a boundary, which bends them. They diffract when they spread out through a gap or around an edge, most strongly when the gap is about the size of the wavelength.
Reflection is a wave bouncing off a barrier; refraction is a wave changing direction as it changes speed at a boundary; diffraction is a wave spreading out through a gap or around an edge.
In refraction the frequency stays the same; the speed and wavelength change.
Send waves at a barrier, across a boundary, and through a gap, and watch them reflect, refract and diffract.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
When a wave bounces off a barrier, this is...
When a wave changes direction as it changes speed at a boundary, this is...
When a wave spreads out as it passes through a gap, this is...
Diffraction through a gap is greatest when the gap is...
Each effect has a clear cause and a clear rule.
When a wave refracts, its frequency does not change; only its speed and wavelength do. And diffraction is most noticeable when the gap is about equal to the wavelength, not simply when the gap is small.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Water waves move from deep into shallow water and slow down. They will...
When a wave reflects off a straight barrier, the angle of incidence...
A wave passes through a gap much wider than its wavelength. It will...
Four wave skills down. The Extended look at diffraction is next.