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

We have a thin rod of length 10 cm uniformly charged with a total charge of + 40 nC . A small glass bead charged to + 6 nC is located 4 cm from the center of the rod. What is the force on the bead?

2. Relevant equations

E = integral of K dq /r^2 and Q = lambda L and therefore dq = lambda dy since y will be variable of length

L = length of rod d = distance from rod Lambda = Q/L

3. The attempt at a solution

The y component of the elec field is 0 due to symmetry.

Esub x = KQ / L [integral from - L/2 to + L/2 of d / (y^2 + d^2)^(3/2) dy

I can do this problem except for evaluating this integral. My book shows that this integral

d divided by (y^2 + d^2)^(3/2) dy when evaluated is y divided by [ d (y^2 + d^2)^(1/2) ] Can someone go over the steps to this integration PLEASE. I can take it after that and get a force but I can not figure out how this integral is done. THanks Frostking

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# Homework Help: Electric Field of a thin rod

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