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Homework Help: Work done

  1. Aug 9, 2016 #1
    1. The problem statement, all variables and given/known data
    for the work done θ , after combining all three , the work done should be = 2x(e^y) + (z+1)(e^z) - (e^z) + k , am i right ?
    why the author stated it is x(e^y) + (z+1)(e^z) - (e^z) + k ?
    There's x(e^y) in equation (i) and (ii)

    2. Relevant equations


    3. The attempt at a solution
    θ= (x)(e^y) + f(y,z) + (x)(e^y) + g(x,z) + (z+1)(e^z) - (e^z) + h(x,y )
    = 2(x)(e^y) + (z+1)(e^z) - (e^z) + k
     

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  2. jcsd
  3. Aug 9, 2016 #2
    No, the author is right. You shouldn't simply add the RHS of the equations. The expressions which are common don't need to be added. In your example, if you had ##2xe^y## ( like you thought), you wouldn't get ## \frac {\partial \phi}{\partial x} = e^y## and ## \frac {\partial \phi}{\partial y}= xe^y##
     
  4. Aug 9, 2016 #3
    I would never have solved it this way. I would have expressed everything in terms of t.
     
  5. Aug 9, 2016 #4
    Exactly, I too would have done the same.
     
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