Resultant Force on Q1 from Three Point Charges

[stumped23]

Three point charges with a distance a between them (as shown). What is the resultant force on q1?

Is this correct or am I doing this completely wrong?

edit: that should be Q1 multiplied by Q3 not adding

http://img513.imageshack.us/img513/3668/untitledxr7.jpg

 

[liorda]

You're partially right. The F's on your answer should be vectors, since the forces applied on the charge by different charges are on different directions (radial ones)

 

[stumped23]

Thanks. I knew adding the two forces like that couldn't be right

so if i find the value of F1 and F2 (angle of 60 degrees between them), and resolve them into one resultant vector force.. that will be the correct answer?

 

[liorda]

Yes.
$${\vec{F}}_{TOTAL} = \vec{F}_1 + \vec{F}_2$$