- 2

- 0

**1. The problem statement, all variables and given/known data**

Given three equal(1,2,3) (negative) charged particles , forming a circle ; and a charged particle on the center of the circle(#4).

360/3 = 120 . The angle between the charged particles are 120 degrees.

**2. Relevant equations**

1) First Case : Find the resultant force on q4 applied by q1,q2,q3 knowing that q1=q2=q3=q4.If q4>0.

2)Second case : Same as before , if q4<0.

Comment on the solution : Is there equilibrium

**3. The attempt at a solution**

F4 = F1/4 + F2/4 + F3/4 : All as a vector.

But F1/4 +F3/4 = -F2/4 : Replace in the equation F4 = 0 ,there is equilibrium . . .

Thanks in advance.