1. The problem statement, all variables and given/known data Two small spheres, each of mass 2.00 g, are suspended by light strings 10.0 cm in length. A uniform electric field is applied in the x direction. The spheres have charges equal to -5.00 x 10^-8 C and +5.00 x 10^-8 C. Determine the electric field that enables the spheres to be in equilibrium at an angle theta= 10.0° to the vertical. 2. Relevant equations F=Eq,F=KqQ/r^2 3. The attempt at a solution For the equilibrium of whole system, I have applied the forces along the x-axis. So then attraction force between two charges=The sum of forces on (-) and (+) charges by the field.And I have noticed that tensions are canceling each other. (8.99x10^9)(5x10x10^-6)^2/(2x0.1sin10)=2E(5x10^-6) and I have got E=6.47 x 10^3 N/c for the answer but unfortunately answer was incorrect. Was there any thing wrong with my equations? Thanks.