Homework Help: Coulomb's Law: Ring of Charge

1. Jan 24, 2010

yb1013

1. The problem statement, all variables and given/known data

A ring-shaped conductor with radius a = 2.20 cm has a total positive charge Q = +0.145 nC uniformly distributed around it, as shown in the figure below. The center of the ring is at the origin of coordinates O.

(a) What is the electric field (magnitude and direction) at point P, which is on the x-axis at x = 50.0 cm?

(b) A point charge q = -2.00 µC is placed at the point P described in part (a). What are the magnitude and direction of the force exerted by the charge q on the ring?

3. The attempt at a solution

I only have a couple questions left on my homework, and I got through all of them, but I'm really just not sure what to do on this one. It seems like it's similar to all the others where I would use Coulomb's law to and break it down into components but I'm not sure. Is there a simple way to take into account a ring?
And Im pretty sure that theres not going to be any y magnitude because it will all cancel out, so we're just dealing with the x?

2. Jan 24, 2010

rl.bhat

You have stated that the center of the ring is at the origin of coordinates O. In which plane the ring is lying?
You have not posted the figure.