Electric field on the x-axis of a semicircle

[eckerm]

Homework Statement

There's a charged semicircle, the ends of which are on the x-axis and it extends into the positive y-axis. It has uniform line charge density. I need to find the electric field at an arbitrary point on the x-axis that's not the origin.

Homework Equations

I don't know.

The Attempt at a Solution

I don't even know where to start. Even just starting me off would be much appreciated.

 

[BvU]

Hello eckerm,

The guidelines prevent me from helping you in this state of affairs. 'Dunno' doesn't count in the PF culture. Look around a bit (hyperphysics, for example) and come back with a formula.

And a sketch of the situation might be useful too. I for one, can't make out whaat your configuration looks like. It will be difficult to calculate the field at the points where the 'ends are on the x-axis' if I take your description literally.