Hi there, I am having a bit of difficulty with this problem dealing with a little more difficult application of Couloumbs Law.(adsbygoogle = window.adsbygoogle || []).push({});

A large electroscope has two wires that are 75-cm long w/22g balls at the ends. When charged, all the charge resides on the balls (Q/2 for each ball) If the wires each make a 30 degree angle with the vertical, what total charge Q must have been applied to the electroscope?

So I set up my free body diagrams and I know how to figure out the weight force and i believe i can get tension--- but what should I be doing to know how much force electrical force is applied (Repulsion in this case since both charges are positive) to make that 30 degree angle to the vertical?

I need to be thinking back to mechanics a little bit =P

Any help would be appreciated--- thank you.

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# Application of Coloumb's Law to electroscope

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