1. The problem statement, all variables and given/known data Two point charges are placed on the x-axis as follows: one positive charge, q_{1}, is located to the right of the origin at x= x_{1}, and a second positive charge, q_{2}, is located to the left of the origin at x= x_{2}. What is the total force (magnitude and direction) exerted by these two charges on a negative point charge, q_{3}, that is placed at the origin? Use [tex]\epsilon_{0}[/tex] for the permittivity of free space. Take positive forces to be along the positive x-axis. Do not use unit vectors. 2. Relevant equations Coulomb's Law: F = [tex]\frac{1}{4\pi\epsilon_{0}}\frac{\left|q_{1}q_{2}\right|}{r^{2}}[/tex] 3. The attempt at a solution MasteringPhysics keeps giving me a "Check your signs error". Yet, as far as I can tell, I should be subtracting the force which is going left / the negative direction (ie, q_{2}) from the force going to the right (ie, q_{1}). Any hints?
My apologizes if the "attempt at a solution" section appeared blank for anyone -- I have changed the link so that users who are not logged in can now see the link.
u can find the electric field at the origin from the charge q1 and q2 and then u can find the force using F= q3 * E .. try this one, I hope it will work