LuduminaWA-13 · WA-U4 · Planned
Visible colour, filters and reflection
Learning objectives
Explain opaque colour and filters through selective absorption/reflection/transmission; distinguish specular/diffuse reflection and transparent/translucent.
8463 §§4.6.2.6 / No Trilogy counterpart
DfE single-science pp.37–39 / Combined pp.32–33. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.6; MS5b.
Explanation
An opaque object’s appearance depends on incident wavelengths and which it reflects. Filters selectively transmit and absorb; they do not manufacture missing light. Rough surfaces reflect at many local orientations, producing diffuse reflection while each local ray obeys the reflection rule.
Concepts, equations and units: Visible wavelength bands; no new equation; source spectrum matters.
Prediction, demonstration and game exercise
Predict, observe, explain
Illuminate coloured objects with white and single-colour light; show rough/smooth reflected rays.
Planned learner game exercise
Select light/filter combinations to reveal a coded object; predict black appearances when available light is absorbed.
Independent practice
Explain three source–filter–object cases and draw smooth/rough ray patterns.
Original practice example · Separate Physics
An ideal red-reflecting object is lit only by blue light, which it absorbs. How does it appear?
Show working and model answer
Working / reasoning
No red light is incident to reflect, and the supplied blue light is absorbed.
Answer
Black or very dark in the ideal model.
Exit check and success criteria
Two colour predictions correct with wavelength explanation and both reflection patterns consistent.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
A red object always looks red; filters add their colour; diffuse rays violate reflection law.
Practical preparation
Optional colour/filter investigation, AT4,8.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.