Image: Jon Candy @Flickr

The story

The flame that will burn during the London Olympic Games was lit at Olympia, the birthplace of the Ancient Olympics, last Thursday. The torch is lit using the same method as it was at the ancient Olympic Games, a parabolic mirror.

Teaching idea and resource

This story could be used in a lesson on reflection of light for KS3 or KS4 classes. The resource I have provided includes a starter activity (slide 1) to get the students thinking about  how the torch is lit as well as a student activity (slide 3) and a handout (slide 4). This asks them to draw in the light rays on the parabolic mirror using the law of reflection before writing an explanation as to how it works. I have included keywords but these can be removed for higher ability students. A model answer is shown on slide 5.


They could then go on to look at how this technique is scaled up in solar furnaces.

Image: Llez @ wikipedia commons

The largest solar furnace at Odeillo in France (shown above) can produce temperatures of up to 3500°C as this video clip shows.

Weblinks

How Olympic torches work website

A parabolic mirror is used in solar ovens. This website explains how they work in more detail.

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