1. The problem statement, all variables and given/known data(adsbygoogle = window.adsbygoogle || []).push({});

The word document with the problem is attached below.

2. Relevant equations

dE=kdQ/r2^{2}

Ex=Ecos∅

3. The attempt at a solution

dE=kdQ/r^{2}

E=kλ∫dy/(x^{2}+y^{2}) (integrating from y= -L/2 to L/2)

Ex=2kλ∫xdy/(x^{2}+y^{2})^{3/2}(change integration to y= 0 to L/2, multiplying expression by 2)

Let y=xtan∅

dy=x(sec∅)^{2}d∅

=2kxλ∫x(sec∅)^{2}/x^{3}(sec∅)^{3}d∅

=2kλ/x∫cos∅ d∅

=2kλ/x(sin∅)

=2kλ/x(sin(arctan(y/x)) (evaluated from y=0 to y=L/2)

=2kλ/x(y/(x^{2}+y^{2})^{1/2}(evaluated from 0->L/2)

=2kλ/x(L/2)(x^{2}+(L^{2})/4)^{1/2}

=((1.8X10^10)λL/(2x))*(1/x^{2}+(L^{2})/4)^{1/2}

This isn't the correct answer, though I don't know what actually is. I would appreciate any help or guidance!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Electric Field of a Straight Wire (now with the attachment)

**Physics Forums | Science Articles, Homework Help, Discussion**