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!

Homework Help: Qucik easy question

  1. Apr 1, 2004 #1
    alright.... i just figured out two magnetic fields, and now the question is asking me to find out the net magnetic field and the direction, for the net i would just subtract the biggest from the smallest, and then i use the Right hand rule to figure out the direction of the B field.... is this correct.
  2. jcsd
  3. Apr 1, 2004 #2
    Try vector addition, not a combination of vector addition and the cross product.

  4. Apr 1, 2004 #3
    so u mena like set the bigge one - the smaller one = 0?
  5. Apr 1, 2004 #4
    It doesn't matter which one's bigger or smaller.

    You are familiar with vector addition, correct?

    [tex]\vec{v} = <v_x,v_y>[/tex]
    [tex]\vec{v} + \vec{u} = <v_x,v_y> + <u_x,u_y> = <v_x + u_x,v_y + u_y>[/tex]

    And bigger - smaller = 0 would imply that bigger = smaller, just for reference.

  6. Apr 2, 2004 #5


    User Avatar
    Science Advisor

    No, when he said "try vector addition", believe it or not, he actually meant "add". You already know the two fields separately- the "net" force field is exactly the same as the sum- if the two forces are in the same direction, then the "net" force is "larger" (in strength)- if they are in opposite directions, the sum is smaller (in strength). In any case, the vector properties will take care of that- just add the vectors.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook