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These resources have been reviewed and selected by STEM Learning’s team of education specialists for factual accuracy and relevance to teaching STEM subjects in UK schools.

Obedient Ray

This investigation looks at two mirrors fixed at a point. A ray of light enters the set-up, bounces around and then exits along the same path. The task is to find the angle between the mirrors. The result is 45° divided by the number of times the light strikes the mirror.

A derivation of the result involves repeated use of Pythagoras’ theorem and working with surds.

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