What is the Potential Difference in a Non-Uniform Electric Field?

[PhysicsInNJ]

Homework Statement

The electric field in a region of space has the components Ey = Ez = 0 and Ex = (4.00 N/C·m) x. Point A is on the y axis at y = 3.60 m, and Point B is on thex axis at x = 3.00 m. What is the potential difference VB − VA?

Homework Equations

Vb- Vi = -∫^b_a E * dS

The Attempt at a Solution

The integral should become E*d, or 4*0.6 , but that is incorrect
The correct answer is -18V

 

[gneill]

The Attempt at a Solution

The integral should become E*d, or 4*0.6 , but that is incorrect
The correct answer is -18V

Where does the 0.6 come from? Note that the two points are on different axes.

 

[rude man]

What's a good choice of path integration? Does the datum y = 3.6, as opposed to some other y number, have any significance?

 

[vela]

The integral should become E*d

In addition to what the others said, $\Delta V = Ed$ only holds for uniform fields. You don't have a uniform field in this problem.