10-31. Figure 10-16 shows the positions of two a particles (charge on each is +2e) and an electron. What are the magnitude and direction of

(a) the resultant force on the electron?

(Hint: choose the +x axis along the line from the electron to the right-hand a particle.)

[Ans.(a) 1.31X10^-8 N at 13.3° to left of line from electron to right-hand a]

 

We are going to evaluate the force using components so we need to choose an x, y coordinate system. There is no such thing as a "wrong" coordinate system but some are better than others because they simplify the solution. Which is best?