Electric forces

Question

Given the arrangement of charged particles shown in the figure below, find the net electrostatic force on the Q₂ = 3.00 nC

 charged particle located at the origin. (Express your answer in vector form. Assume Q₁ = −15.00 nC

 and Q₃ = 6.00 nC.)

F = 

 

 N

Answer 1

First let's find the force of Q1 on Q2.

F₁₂ = kQ1Q2/d^2 = k x -15nC x 3nC / (3.5 x 10^-2)²

9 x 10⁹ x 15 x 10^-9 C x 3 x 10^-9 C / (12.25 x 10^-4) = 4.05 x 10^-6N (-x direction) To the Left

F₃₂ = kQ₃Q₂/d^2 = k x 3nC x 6nC / (1.5 x 10^-2)²

9 x 10⁹ x 3 x 10^-9 C x 6 x 10^-9 C / (2.25 x 10^-4) = 1.62 x 10^-4N (-x direction) To the Left

F_total = F₁₂ + F₃₂ = (1.62 + 0.00405) x 10^-4 = 1.62405 x 10^-4 N (in the -X direction)