# Like charges on two identical balls

Two identical metal balls bear the same amount and sign of electric charge because they have been touched together. The mass of each ball is 2.00 grams. One ball is mounted on an insulating post. The other ball is suspended from a bifilar silk thread suspension system so that it can move on a 0.500 meter radius. When the two balls are 0.0500 meters from each other in the same horizontal plane, the suspension makes an angle of 30.0 degrees from the vertical. What is the charge (in Coulombs) on either of the balls? (I have drawn a picture of the apparatus, but I'm not sure if it is correct - how can they be in the same horizontal plane @ 30 degrees and still swing and touch?)

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...ected by an angle of 30 degrees because of the electric force repelling them. The forces acting on the suspended ball are:

(x refers to the horizontal direction and y to the vertical)
Tension force: T that has Tx and Ty components given by
Tx=T sin 30 to the ...