Strength of electrostatic force

[bastige]

Homework Statement

Three point charges are located at the corner of an equilateral triangle. The Coulomb constant is 8.98755 X 109 N*m2 / C2
What is the strength of the electrostatic force on the top charge? Answer in units of N.

Length of each side is .19m

Photo: http://rs300l32.rapidshare.com/files/102321145/876fa4a066b34fc617aee82211671f78.jpg

Homework Equations

F= [k(q1)(q2)] / r^2

The Attempt at a Solution

I know I must get F1 & F2, but then I don't know what to do

F1=[k(2.68E-6)(1.32E-6)] / .19^2 = .880730107

F2= [k(2.68E-6)(-3.93E-6)] / .19^2



I

 

[liorda]

can you please upload the diagram to imageshack.us?

 

[Snazzy]

Vector analysis. Break the force into its components.

 

[bastige]

I don't know how to do vector analysis, can you add more info?

http://img246.imageshack.us/img246/3104/876fa4a066b34fc617aee82op8.th.jpg