Three identical point charges, each with a charge equal to q, lie in the xy plane. Two of the
charges are on the y axis at y = -a and y = +a, and the third charge is on the axis at x = a.
(a) Find the potential as a function of position along the x axis.
(b) Use the Part (a) result to obtain an expression for Ex(x), the component of the electric field
as a function of x. Check your answers to Parts (a) and (b) at the origin and as x approaches 1
to see if they yield the expected results.

Question

Three identical point charges, each with a charge equal to q, lie in the xy plane. Two of the
charges are on the y axis at y = -a and y = +a, and the third charge is on the axis at x = a.
(a) Find the potential as a function of position along the x axis.
(b) Use the Part (a) result to obtain an expression for Ex(x), the component of the electric field
as a function of x. Check your answers to Parts (a) and (b) at the origin and as x approaches 1
to see if they yield the expected results.

anonymous · Answer

U need to make use of vectors man.. 

if u use i j k as unit vectors in x, y and z direction then

$$q_1 = a j ,.....q_2 = -aj..... q_3= ai$$

then take a random point on the x axis as $$r = x i $$

anonymous · Answer

|dw:1376346888497:dw| 

net potential = potential due to all charges in region.