# Coulomb's law, one charge placed between two others

1. Sep 11, 2010

### uia

1. The problem statement, all variables and given/known data
distance between two electrical charges q1=10nC, q2=16nC is 7mm , what force will act at third charge q3=2nC, placed between the first two charges 3mm far from the smaler charge and 4 mm far from the larger charge.

2. Relevant equations
Fc=k*|q1||q2|/r2

3. The attempt at a solution
F1,3=0,02(N)
F2,3=0,018(N)
then F=F1,3-F2,3=0,02N-0,018N=0,002N=2(mN)
am I right?

Last edited: Sep 12, 2010