4-WAV-02a
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Contents
Outcomes
- Pupils can state and use the Law of Reflection.
- Pupils can explain refraction as due to a change of speed in different media.
- Pupils can predict the change in direction of a wave due to refraction, including examples using light (including dispersion) and in water, using wave front to explain what is occurring.
Specification References
Starter
- Ask pupils how a mirror works. Link reflection to smoothness of a surface.
- (If you're feeling really brave you could ask why mirrors reflect things right-to-left but not top-to-button.)
Main Body of Lesson
- Use small bulb, radiant heater, two parabolic mirrors, camera and temperature probe to demonstrate that heat waves are reflected just as light waves are.
- Pupils carry out Law of Reflection experiment and discover (for themselves) the Law of Reflection.
- Pupils carry out a "qualitative experiment on Law of Refraction". I think that means that they don't need to know Snell's Law, and you can avoid working with sine functions.
Plenary
- Refraction: Look at the "Spear Fisherman Problem". Why is it that a spear fisherman mustn't aim for the fish itself, but take refraction into account.
- Reflection: Complete corner retroreflector worksheet.
Homework
Additional Information
Resources Required
Textbook References
- Pople 7.02 pp. 142-145