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Homework Help: Mastering physics: electric field of point charges

  1. Mar 7, 2010 #1
    1. The problem statement, all variables and given/known data

    Two point charges are placed on the x axis. The first charge, q1= 8.00 , is placed a distance 16.0m from the origin along the positive x axis; the second charge, q2= 6.00 , is placed a distance 9.00m from the origin along the negative x axis.

    1011307.jpg

    Calculate the electric field at point A, located at coordinates (0m , 12.0 m).
    Give the x and y components of the electric field as an ordered pair. Express your answer in newtons per coulomb to three significant figures.

    EAx, EAy=________________________ N/C



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 7, 2010 #2
    can you please show your attempt of solution so we can help!
     
  4. Mar 8, 2010 #3
    i don't know which equations to use
     
  5. Mar 8, 2010 #4
    E = kq/r^2
    Where E is the electric field, k is a constant = 9x10^9, r is the distance from the charge to the point where you want to find the electric field..

    Find the electric field produced from q1 at point A , then find the electric field from q2 at point A .. Add them together to get the total electric field at that point ..

    Note: the electric field is a vector, when you add you should use vector addition..

    I hope it is clear enough for you start solving the question..
     
  6. Feb 2, 2011 #5
    For these types of problems could someone please explain how you find which of the components x or y cancel. Also how can you tell if E_1 and E_2 are negative or positive? I am pretty sure i found E_1 and E_2 i just don't understand how you can tell to add both together or subtract one from the other.
     
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