Two pith balls below each have a mass of 5.0 g and equal charge. One pith ball is suspended by an insulating thread. The other is brought to x = 4.0 cm from the suspended ball. The suspended ball is now hanging with the thread forming an angle of 30.0° with the vertical. The ball is in equilibrium with FE, Fg, and FT. Calculate each of the following.

Question

Two pith balls below each have a mass of 5.0 g and equal charge. One pith ball is suspended by an insulating thread. The other is brought to x = 4.0 cm from the suspended ball. The suspended ball is now hanging with the thread forming an angle of 30.0° with the vertical. The ball is in equilibrium with FE, Fg, and FT. Calculate each of the following.
Fg = 0.049
FE = 0.028 
What is the charge on the pith balls?

bobpursley · Answer

Let me get it straight? You are given the electric force, and the distance, and you want the charge? F=Kq^2/r^2 solve for q.

Adam · Answer

I got the answer as 1E-7, but it wouldn't accept the answer, any ideas?