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Force acting on area

  1. Mar 15, 2016 #1
    1. The problem statement, all variables and given/known data
    dA lies on x and y aixs , right ? the author gave that the volume flow rate thru element A is ucos(theta)dA , why not
    usin(theta)dA ? if u ' = ucos(theta) , it will become parallel to dA , right ? since u' will be parallel to x-axis.....
    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

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  2. jcsd
  3. Mar 15, 2016 #2


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    dA is in the yz plane
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