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Homework Help: Work done by force on moving particle

  1. Oct 30, 2004 #1
    My problem is:

    A particle is acted on by a force, F=-(5yx^2)i + (4y^3)j
    Calculate the work done by F as the particle moves from point (-2,4) to point (5,10)? F is in Newtons and all x's and y's are in meters.

    I think that I need to integrate each piece using the points as limits, but I'm not sure what I do with -(5yx^2) Do I only need to integrate with respect to x since it is with the "i" portion of the F?
    Last edited: Oct 30, 2004
  2. jcsd
  3. Oct 30, 2004 #2
    The integral you evaluate when calculating work is called a "Path Integral". From the definition of work,

    [tex]W = \int_a^b \vec F \cdot d\vec r = \int_a^b F_x dx + F_y dy + F_z dz[/tex]

    Thus you have three integrals: one over each coordinate.

    So you are right....the integral over [tex]F_x[/tex] only affects the x variable.
  4. Oct 30, 2004 #3
    Thanks so much!
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