Question

A proton is located at the origin of a rectilinear coordinate system. An electron is at x=4pm, y=3pm. What is the force on the proton. Give your answer in unit vector notation.

Answer 1

You can do this in each direction

Fx= kqq/x^2 fy= kqq/y^2

then the resultant force will be the vector addition of these two.