Recent content by boris.rarden

thanks, looks like i was able to show it after all following your ideas and the log expansion.

Actually, is there an equivalent approximation trick for log ? I'm stuck because I have to consolidate 1/r and log( f(r) ). Should I use Taylor series ?

Homework Statement I'm trying to prove that Electric field away from a line segment of charge, is equivalent to the field away from a point charge, provided I observe from far enough. Homework Equations Ignoring all the constants: potential_line = log( (sqrt(r^2 + a^2) + a) /...

imagine a charge placed inside a closed conducting shell (a hollow metal box or sphere) Feynman says: - no static distribution of charges inside a closed conductor can produce any fields outside. The fields on the two sides of a closed conducting shell are completely independent. but...