Work of Electric Field Problem, can't find mistake

[jigs90]

Homework Statement

I posted the question on cramster at
http://answerboard.cramster.com/physics- ...
so you could see the picture.

Homework Equations

W = qV = kq1q2 / r

The Attempt at a Solution

I figure out A, B, and C, (which are the x component, y component, and the electric potential, but I can't figure out how to do part D, (which is the work to asseble the four charges). Please help! I tried to you W=qV, but that didn't work.

My Answers were
A) was 24.4
B) was 77.96
C) was 2.719x10^3

Work done in assembling +6 uF and -6uF is zero

Total work =kq1q2/r=9*10^9*8.2*16.4*10^-12/(47sin(60

Total work =2.97*10^-2 J

 

[jigs90]

The link was

http://answerboard.cramster.com/physics-topic-5-189871-0.aspx

sorry

 

[jigs90]

Wait, should I calculate each PE separately and then add them together? Would there be 6 different PEs?

 

[jigs90]

Figured it out...

 

[mer584]

Upon brief inspection, What I would do is use the formula V= kQ/R for each point in relation to P. Then you can add these based on the sign of the charge to solve for W=qV. Give that a try.