What is the Net Force on Charges in a Square?

[RemoteDoc]

Homework Statement

https://img.skitch.com/20120425-x1ekh2xqk9j61xqk83uyspaf75.jpg

Homework Equations

F=Kq1q2/r^2
E=kQ/r^2

The Attempt at a Solution

Answer choice E is not listed in screenshot, but states that there is no Net force on the Charge. I picked E, but I'm second-guessing myself.

 

[Villyer]

What made you choose E? Are there other options that seem plausible to you which make you second guess yourself?

 

[RemoteDoc]

Well, I guess I was hoping for a more quantitative way of understanding the vector sums in this equation, without having supplied values.

 

[RemoteDoc]

Ultimately I just plugged in some variables and my answer held up.