Electric field due to a line of charge: HELP

[afcwestwarrior]

Electric field due to a line of charge: HELP!

Homework Statement

Positive charge q = 7.81 X 10^-12 C is spread uniformly along a thing nonconducting rod of length L = 14.5 cm or .145 m. What are (a) magnitude and (b) direction (relative to the positive direction of the x axis) of the electric field produce at point P, at distance R = .06 m from the rod along its perpendicular bisector?

Homework Equations

E = k * (q/(r^2))

dq = lamda * dx

replace q with dq

The Attempt at a Solution

 

[chrisk]

Use symmetry and integration to solve. Try drawing the line charge along the y axis, pick a point on the line charge, dq, and express dE at a point P along the x-axis created by dq.