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Homework Help: Relationship between Electric Fields and Distance from point charge?

  1. Oct 25, 2011 #1
    Relationship between Electric Fields and Distance from point charge??

    1. The problem statement, all variables and given/known data
    v4ctug.jpg


    2. Relevant equations
    E= kq/r^2


    3. The attempt at a solution
    K so looking at the graph, I noticed that there is a inverse-square relationship between the electric field and the radius/distance.

    So I considered that there would have to be a curved slope on a 1/r^2 graph, because the x-axis is squared.

    Wouldn't any graph have a curved slope when the x-axis is squared?

    For example, a simple equation like y = x^2 results in a curved slope, because the y-axis point is always squared of the x-axis point.

    Wouldn't that reasoning work with this?

    So my answer is A.



    But my friend is saying that the graph would be curved with just 1/r.

    And straight with 1/r^2. So her answer is C.

    Which is right? Other ppl in my class are also saying that the answer is C as well, but i dont see why.

    A lot of people are saying I'm thinking too hard and reaching a wrong conclusion, but they don't know how to explain.

    What's wrong with my theory and what's right about my friend's?


    Please explain T__T
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Oct 25, 2011 #2

    SammyS

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    Re: Relationship between Electric Fields and Distance from point charge??

    What would the markings look like on the horizontal axis of the 1/r2 graph ?

    What would they look like on the 1/r graph?
     
  4. Oct 25, 2011 #3
    Re: Relationship between Electric Fields and Distance from point charge??

    On the 1/r^2 graph, markings on the x-axis would go

    1, 1/4, 1/9, etc

    On the 1/r graph, markings would go

    1, 1/2, 1/3, etc

    This... Does not help me get it.

    Please continue though T_T
     
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