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Electric field question

  1. Feb 5, 2010 #1
    1. The problem statement, all variables and given/known data
    A thin, semi-infinite rod with a uniform linear charge density (lambda) (in units of
    C/m) lies along the positive x axis from x = 0 to x = 1; a similar rod lies
    along the positive y axis from y = 0 to y = 1. Calculate the
    electric field at a point in the x-y plane in the first quadrant.

    2. Relevant equations
    This is a calc based course. Intergration is required for this problem. If you need a diagram I do have one.


    3. The attempt at a solution
     
  2. jcsd
  3. Feb 5, 2010 #2

    fluidistic

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    Gold Member

    Hi and welcome to the forum!
    In this forum you have to show an attempt, so that we can help you where you're stuck.
     
  4. Feb 5, 2010 #3
    This is one question that I am not that sure how to get started with.
     
  5. Feb 5, 2010 #4

    fluidistic

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    Gold Member

    [tex]d\vec E = \frac{kdQ \vec r}{r^3}[/tex]. What is worth dQ in the case of a straight segment of length dx of the rod?
    Once you have [tex]d\vec E[/tex], you just have to integrate (choosing the appropriate limits of integration) to get [tex]\vec E[/tex].
    I suggest you to start by drawing the situation. Put a point [tex](x_0,y_0)[/tex] in the first quadrant. Tackle the problem first with the x-axis rod. Calculate the E field due a small element dx of it, then integrate to get the E field (in point [tex](x_0,y_0)[/tex]) due to the whole x-axis rod.
    Do the same for the y-axis rod and sum them up. Don't forget that they are vectors.

    I hope it helps. Feel free to post any difficulties you encounter.
     
  6. Feb 8, 2010 #5
    ok so I understand that for intergrating the 2 rods you set them up as
    [tex]\int dE1x+dE2x[/tex] and the same for the y component but I am kinda stuck on what is next.
     
  7. Feb 8, 2010 #6
    ok so I understand that for intergrating the 2 rods you set them up as
    [tex]\int dE1x+dE2x[/tex] and the same for the y component but I am kinda stuck on what is next.
     
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