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Homework Help: Line integrals?

  1. May 12, 2008 #1
    1. Evaluate the line integral∫F . dr with F = 3(-y,x,0) from (a,0,0) to (a,0,2πb) along a straight line.

    2. Do the same along a circular helix between the two points, parameterised as r = (a cosλ, a sinλ, bλ)

    3. Compute the curl of F. How does this relate to the two integral calculations above?

    I know Curl = \nabla x F

    My notes on this don't seem to be that great, and I'm just completely lost, tbh.

    Any help?
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. May 12, 2008 #2
    It should seem obvious that, since there is no force applied in the z in the first one, no work is done. From experience, I know that it is again zero in part 2. What do you get for the curl? Solving for it should show you tell you something important.
  4. May 12, 2008 #3


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