- #1

jlmccart03

- 175

- 9

## Homework Statement

__Problem # 4:__[/B]

A thin semicircular rod has a total charge +Q uniformly distributed along it. A negative point charge -Q is placed as shown. A test charge +q is placed at point C. (Point C is equidistant from -Q and from all points on the rod.)

http://imgur.com/AeVfddb

_{P}and F

_{R}represent the force on the test Charge due to the point charge and the rod respectively.

__Part C:__A second negative point charge -Q is placed as shown.

http://imgur.com/eYEOkPc

Is the magnitude of the net electric force on +q greater than, less than, or equal to the magnitude of the net electric force on +q in part b? Explain.

Whole Problem

http://imgur.com/VbAtlg5

## Homework Equations

F = kq

_{1}q

_{2}/r

^{2}

Also basic knowledge of electric forces based on vector math and x/y - components.

## The Attempt at a Solution

So I solved part b (hopefully correct), but I want to say that the magnitude of the net electric force on +q will be less than the one found in part b since the -Q charges would cancel out as they are the same distance thus same magnitude, but opposite directions. However, I am confused on how the semicircular rod affects this as it is right there between it and the -Q charge.

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