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Homework Help: Dtermining dimensions.

  1. Aug 27, 2012 #1
    1. The problem statement, all variables and given/known data
    Let P represent a force and x, y, and z represent distances. Determine the dimensions for each of the quantities listed below.

    I attached the problem I need help with. (it's a small picture)

    So I'm a bit confused since the it involves both dx and dy.

    The dimensions for P is (ML/T^2)
    Where M=mass

    Then I have to differentiate it twice but with two different variables. Since x and y refer to distances and the only distance found in that equation is L.

    Would that mean the dimensions for dP/dx = M/T^2 ?

    If so, would that mean the answer to the 2nd derivative still be the same answer since they're differentiating between different variables? (I'm not sure if I worded this right, but I remember from Calc III something similar)

    On a side note. I took calculus quite a while ago so some of this I might have forgotten.
    The picture I provided, that is not equivalent to (dP/dx)*(dP/dy) right?

    Attached Files:

    Last edited: Aug 27, 2012
  2. jcsd
  3. Aug 28, 2012 #2
    A derivative is the limit of a certain ratio. It has the same dimensions as the ratio. What dimensions does the ratio have?
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