- #1
Pual Black
- 92
- 1
Homework Statement
Hi,
The question is
"
Three point charges (q,−2q,q) are located in a straight line with separation a and with the middle charge (−2q) at the origin of a grounded conducting spherical shell of radius b ..."
I have found a solution for this problem but there is one step that I don't understand. I have uploaded the pdf file.
Last page the term ##-\frac{1}{r}## vanishes and at the bottom of the page the
##\frac{1}{b}-\frac{1}{r}## vanishes too. Can you tell me why?