# What should my next step be after drawing a diagram? [closed]

I was training with some example exams, and I found out a problem that I don't know how to start with it, not even a main formula...

Two balls with masses of 0.5g each hang on threads 0.8m long each tied to a common hook.

What charge has been acquired by the system if, as a result, an angle 2α=15º has been established between the threads?

Well, this is the maximum point I have reached... and I don't know if this actually have any relation with the exercise:

Someone can tell me how to start?

Thank you very much in advance...

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Hi Anne - you seem to have your set up correctly. Try drawing a free body diagram and consider the different forces involved. Also, there is a simple expression for the force between two charged bodies that should help clear it up. – Jen Jan 2 '12 at 6:10
FBD will solve your problem, use the angle for deducing the angle between forces. – Vineet Menon Jan 2 '12 at 6:39
Hi Anne, and welcome to Physics Stack Exchange! This is not really a homework help site; it's for conceptual questions about physics. Accordingly, if you'd like to ask a homework problem, we expect you to narrow it down to the specific physics concept that is giving you trouble. Just asking "how do I start?" doesn't tell us what you're confused about, or how we can best help you. If you can edit this question to focus on a specific concept, I'll be happy to reopen it. See our homework FAQ for more information. – David Zaslavsky Jan 2 '12 at 7:08

## closed as too localized by David Zaslavsky♦Jan 2 '12 at 7:04

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