Re: shell theorem

winston71 <donkey71@xxxxxxxxxxxxx> wrote:

Hello,
From wikipedia "1. A spherically symmetric body affects external
objects gravitationally as though all of its mass were concentrated at
a point at its center."

I don't understand the integration. I tried to make a computer
simulation (million random points represent a sphere, there is a test
point outside the sphere, calculate and add each gravity force
vector), but the results came out wrong; total force is minimum when
sphere radius touches test point, and gets stronger as sphere radius
gets smaller (number of sphere points is constant and test point
coordinates is constant). Did anyone try such a simulation and got
good results? Thanks.

The simulation should work fine if you used the correct equation and
summed the forces properly...

Force of gravity outside a shell:
http://hyperphysics.phy-astr.gsu.edu/Hbase/mechanics/sphshell.html

Force of gravity inside a shell:
http://hyperphysics.phy-astr.gsu.edu/Hbase/mechanics/sphshell2.html

--
Dave
.

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