more physics help!!?

Question

A small 12.00g plastic ball is suspended by a string in a uniform, horizontal electric field with a magnitude of 103 N/C. If the ball is in equilibrium when the string makes a 30 angle with the vertical, what is the net charge on the ball?

Answer 1

Force F equal to electric field E times the point charge q
F=Eq
q=F/E
Also
F= mg sin (30)

finally
q= mg sin(30) /E
q= 12E-3 x 9.81 m/s^2 x sin(30)/ 1E3=

q=0.000 058 86 = 58.86E-6 C