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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


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    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.
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