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Homework Help: I & j Vector Question

  1. Mar 6, 2010 #1
    Have I done this correctly? Thank you.

    1. The problem statement, all variables and given/known data
    A particle of mass 2kg moves under the action of forces 3i - 12j, and i + 6j.

    (i) Find the resultant force acting on the particle in the form ai + bj
    (ii) Find the acceleration of the particle



    2. Relevant equations
    F = ma


    3. The attempt at a solution

    (i)
    R = 3i + i - 12j + 6j
    R = 4i - 6j

    (ii)
    Using F = ma
    4i - 6j = 2a
    2i - 3j = a

    asquared = 2squared + (-3)squared
    a = square root of (4 + 9)
    a = square root of 13
     
  2. jcsd
  3. Mar 6, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Looks good. (But don't leave out units. Physical quantities require units.)
     
  4. Mar 6, 2010 #3
    Thanks very much Doc! :smile:

    Yes, forgot to type the units in. Thanks
     
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