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!

Solving for Electric Field Strength

  1. Oct 19, 2014 #1
    1. The problem statement, all variables and given/known data
    An electric dipole is formed from plusminus.gif 1.0 nC charges spaced 2.4 mm apart. The dipole is at the origin, oriented along they-axis. What is the electric field strength at the following points?
    a. (x, y) = (10 cm, 0 cm)
    b. (x, y) = (0 cm, 10 cm)


    2. Relevant equations
    Pythagorean Theorem a^2 + b^2 = C^2
    F= (kq1q2)/r^2


    3. The attempt at a solution
    I solved for r^2 using the Pythagorean theorem and I got it to equal 0.01 m. Plugging r into the Force equation I got 900N. I think for part a I need to use vectors of the angle created between the x-axis and the hypotenuse (r) but I am not sure how to use that to get the electric field strength.
     
    Last edited by a moderator: Apr 16, 2017
  2. jcsd
  3. Oct 19, 2014 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    F= (kq1q2)/r^2 is a formula for forces between point charges, and it does not take the direction into account.

    Do you have a formula for the electric field of a dipole?
    If not, do you have a formula for the force between two charges in vector form?
     
  4. Oct 19, 2014 #3
    Is it E= (qd)/kz^3
    if d = the distance between the charges and z is the distance I to the point I am solving for?
     
  5. Oct 19, 2014 #4

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    How did k go to the denominator (which needs brackets)? It is the right direction, but that formula needs more vectors to make sense.
     
  6. Oct 19, 2014 #5
    So if the formula is F = (kqd)/z^3,
    I plug in and get [(9.0E9 Nm^2/C^2)*(1.0E-9C)*(2.4E-3m)]/(0.01m)^3 = 21600 N/C
    Is that all I have to do to solve for the x-axis values? and how does this equation relate to part b where both charges are no longer an equal distance to the point on they y-axis?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Solving for Electric Field Strength
Loading...