Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Electrostatic shielding

I cheated; the force is

= q*q*a*r / [(that 4 pi we've been talking about)k0(a*a - r*r)^2] ; mks units

where a is the radius of the metal sphere, r the distance from its centre, and
k0 is 8.85E-12 (permitivity of free space!)

Harnwell ('49) p. 44 (sphere uncharged, insulated, and conducting)


P.s. Solved, if I remember correctly by, as Wm suggests, the "method of

William Beaty wrote:

P.s. I'm rather certain the q inside the sphere will experience a (net)
force if it's not in the center

I believe so. Unlike a hollow shell of mass, the induced opposite charges
on the inner surface of the conductive cage will move adjacent to the
approaching charged object (it will see an "image charge" below the
surface, and experience a dipole attraction force when it's very near the

((((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
EE/programmer/sci-exhibits science projects, tesla, weird science
Seattle, WA 206-789-0775 freenrg-L taoshum-L vortex-L webhead-L