1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Adding electric field vectors

  1. Sep 26, 2009 #1
    I'm a little confused on how the math is supposed to work out when you are adding an electric field from charges with opposite signs. Looking at the image, both of these situations should yield equivalent electric fields at that point right? I get the right answer for when the situation involves two identical charges, but when the charges are opposite i have an extra negative coefficient from the -q which messes up my calculations. I think the problem is that when I draw triangles to try and split up the components that perhaps my Y should be positive for the -q charge, but I'm not sure if/why that should be the case. Otherwise I'm not really sure what I'm doing wrong....any help would be appreciated.
     

    Attached Files:

  2. jcsd
  3. Sep 26, 2009 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi keyfob! Welcome to PF! :smile:
    You seem to be having drawing problems …

    just draw the "second" side of the triangle the other way, so that the internal angle is 180º minus the original angle. :wink:
     
  4. Sep 26, 2009 #3
    Thanks for the help, I'm still a little confused though... I attached an updated picture to this post, is this what you meant? Thanks again
     

    Attached Files:

  5. Sep 26, 2009 #4

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    I don't understand … what are the 6 triangles at the bottom?
     
  6. Sep 26, 2009 #5
    The components of the vectors in the x-y plane
     
  7. Sep 26, 2009 #6

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    But they're all the same. :redface:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Adding electric field vectors
  1. Electric field (Replies: 3)

  2. Electric fields (Replies: 7)

Loading...