Ok, some of you guys will probably find this easy because I've only just started Physics to a very slightly higher level, but whatever. Basically the question is as follows (I'm just remembering this off the top of my head, won't use the proper figures, it's doing it that matters):(adsbygoogle = window.adsbygoogle || []).push({});

A supernova explodes, sending out 500 neutrinos in a spherical explosion. There is a planet 1000km away of radius 50km. How many neutrinos pass through the planet?

IIRC I did this by doing 4πr² on the 1000km, giving the "surface area" of the neutrino explosion. Then doing πr² on the planet's 50km you get it's area. Then divide the area of the planet by the surface area of the explosion, and multiplying that decimal by the number of neutrinos. Was this correct? (I suspect not..)

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# Homework Help: Spherical Explosion (Easy?)

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