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Watt turbine?

Hi. It’s a long time since I (Chris) wrote a blog post, but this Instagram video (no sound) inspired me. 

In the video, the presenter demonstrates how amazing this turbine is by giving it a small push, which lights a number of light bulbs. 

Without knowing the power of the bulbs, this demo is meaningless. The energy given to the bulbs cannot exceed the work done; that's the law. The force isn’t big, and the distance isn’t long, so the work done is small. 

Let’s say 10 N x 1 m =10 J. The time taken is about 1 s, so the power = 10/1 = 10 W. There are 12 bulbs, so each one must be about 1 W. Not particularly powerful!

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