- #1
bobie
Gold Member
- 720
- 2
Hi,
I found this derivation at wiki: http://en.wikipedia.org/wiki/Shell_theorem
Can someone tell me if the theorem is valid only for a solid sphere , or
the pull of a hollow sphere is exacly the same it would be if all the masse where at the center wrt to a mass at any distance D from the centre?
does it apply also when D = R?
If it does can you explain how (apart from the math derivation) if ,say, an electron is on the circumference it gets the maximum pull, and it suffices that it moves 1 mm toward the centre, that pull vanishes all of a sudden? How can such minimal difference in distance cause such a huge result?
Thanks
I found this derivation at wiki: http://en.wikipedia.org/wiki/Shell_theorem
Can someone tell me if the theorem is valid only for a solid sphere , or
the pull of a hollow sphere is exacly the same it would be if all the masse where at the center wrt to a mass at any distance D from the centre?
does it apply also when D = R?
If it does can you explain how (apart from the math derivation) if ,say, an electron is on the circumference it gets the maximum pull, and it suffices that it moves 1 mm toward the centre, that pull vanishes all of a sudden? How can such minimal difference in distance cause such a huge result?
Thanks