1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Pipe in network

  1. Mar 11, 2016 #1
    1. The problem statement, all variables and given/known data
    in the second picture (refer to the circled part) , i can understand the ΣKQ^n , but i dont understand the second one , why it will become ΔQΣKnQ^(n-1) ?

    2. Relevant equations


    3. The attempt at a solution
     

    Attached Files:

    • 01.jpg
      01.jpg
      File size:
      45.8 KB
      Views:
      29
    • 02.jpg
      02.jpg
      File size:
      52.9 KB
      Views:
      43
    • 03.jpg
      03.jpg
      File size:
      35.6 KB
      Views:
      30
  2. jcsd
  3. Mar 11, 2016 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Can't read the exponents. Did you understand 5.13 ?
     
  4. Mar 11, 2016 #3
    not really
     
  5. Mar 11, 2016 #4

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It all hinges on $$\Delta Q << Q \ \ \Rightarrow \ \ (Q + \Delta Q)^2 = Q^2 + 2 Q\, \Delta Q + (\Delta Q)^2\approx Q^2 + 2 Q \Delta Q$$ which is satisfied (maybe not in the first iteration, but later on it is) -- ##\Delta Q## gets smaller and smaller if you do things right.
    (I filled in n = 2 for simplicity)

    You could also see this as a differentiation ( ##{dh\over dQ} = 2KQ {\rm \ \ or \ \ } \Delta h = 2 Q \Delta Q ## ) and then the method is basically the Newton method
     
  6. Mar 11, 2016 #5
    removed
     
  7. Mar 12, 2016 #6

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    ??
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Pipe in network
  1. Network Capacitors (Replies: 7)

  2. RC Network (Replies: 6)

Loading...