4-WAV-02b
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Contents
Outcomes
- Pupils can draw diffraction patterns through "large" and "small" gaps
- Pupils can say whether diffraction will occur based on gap size and wavelength
Specification References
3.8 understand that waves can be diffracted when they pass an edge
3.9 understand that waves can be diffracted through gaps, and that the extent of diffraction depends on the wavelength and the physical dimension of the gap.
Starter
Recap reflection and refraction from last lesson
Main Body of Lesson
When using the strobe on the ripple tank ensure that you warn pupils that the frequency of the strobe may trigger photosensitivie epilepsy.
- Use the ripple tank to observe reflection and refraction if you haven't already
- Use the ripple tank to observe diffraction, vary the separation to see the effect this has on the ammount of diffraction
- Pupils need to be able to draw the pattern through large and small gaps
- Pupils also need to know that diffraction is only very noticable when the gap is a similar size to the wavelength
Plenary
Talk about radio and TV waves and why people can recieve radio but not TV when in the shadown of hills.