Coulomb's law; vector form problem

Dogger

1. Homework Statement
3 charges are placed like shown:

Q1 __4cm____ Q2 ______6cm___________Q3
Q1=-2nC
Q2= 1nC
Q3= 3nC
Find the resultant force and its direction upon the charge Q3.

2. Homework Equations
F=k0*(Q1Q2)/r2
k0-constant, equals to 9*10^9
r-distance

3. The Attempt at a Solution
F1,2=9*10^9*(-2*10^-9*3*10^-9)/(4*10^-2)^2=-11.25*10^-6
F2,3=7,5*10^-6
F1,3=-5,4*10^-6
F(resultant)= 7,5-11,25-5,4 (*10^-6)= -9,15 *10^-6

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TSny

Homework Helper
Gold Member
Welcome to PF!

Does the force F1,2 act on Q3?

Be sure to include units in your answer.

"Coulomb's law; vector form problem"

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