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Homework Help: Vector analysis homework question

  1. Jun 17, 2008 #1
    3 electrons q1, q2, q3 setup in a right angled triangle

    q1
    |\
    | \
    q3-q2

    charges are

    q1 = +2.5 X 10^-17C
    q2 = +3.0 X 10^-17C
    q3 = +3.5 X 10^-17C

    distances between the charges
    q1-q3 = .03 m
    q1-q2 = .05 m

    setup FBD

    \
    \ 2F1
    \
    /
    / 3F1
    q1

    2F1 = k*q1*q2 / .05^2
    = 2.7 X 10^-21N
    3F1 = k*q3*q1 / .03^2
    = 8.75 X 10^-21N

    now I think I use cosine law to figure this out

    Fnet = 2F1^2 + 3F1^2 - 2(2F1)(3F1)cos45

    is this going the right direction, or did I screw up my FBD
     
  2. jcsd
  3. Jun 17, 2008 #2
    find the magnitude and direction of the force acting on q1
     
  4. Jun 17, 2008 #3
    Last edited by a moderator: Apr 23, 2017
  5. Jun 17, 2008 #4

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Hi chemboy! :smile:

    erm … where did 45º come from?

    And are you sure that minus should be there? :smile:
     
  6. Jun 17, 2008 #5

    berkeman

    User Avatar

    Staff: Mentor

    Thread moved to Homework Help forums.
     
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