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November 20, 2014

November 20, 2014

Posted by **Lynn** on Monday, February 21, 2011 at 10:59pm.

So I am attempting to use: I= Power/area

however, I don't have a radius. I know 10% of 100 is 10 so that would be the intensity for that and that the refraction for air should be used but I am missing something...

HELP :)

- Physics -
**drwls**, Monday, February 21, 2011 at 11:35pmThe radius is R = 2.1 m. The light is distributed uniformly over a sphere of that radius, at that distance. So divide 10 W by 4*pi*R^2 and you will have the visible light irradiance.

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