q1 . Draw the FBD of any of the charged ball

Assume that the string connected to it makes an angle  with the vertical .

Then we have T cos = mg

                           T sin = q^2/x^2 sqrt ( 3 ) ( resultant of two forces )

so , tan  = q^ 2sqrt ( 3 ) / x^2 mg = x / sqrt(3 ) l ( from geqmetry with approximation )

  solving for q , we get q = k x^(3/2)

or dq/dt = 3/2k sqrt ( x )dx/dt = c ( since dx/dt = a/ sqrt(x ) )

 so , q = ct , c being a constant ( determine it by putting the value of k )

The calculation is done in CGS units .