posted by Anna .
Three point charges are fixed on the x-axis: 8.7×10^−6 C at x = −0.68 m, −3.0×10^−6 C at the origin, and 2.6×10^−6 C at x = 0.65 m. Find the electrostatic force acting on the charge at the origin due to the other two charges. Let a positive value indicate a force in the positive x direction, and a negative value indicate a force in the negative x direction.
The + charge at -.68 pulls the charge at the origin left (-)
The + charge at +.65 pulls the origin right (+)
F = k*10^-12 (2.6/.65^2 -8.7/.68^2)(3.0)