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!

Homework Help: Geometric similarity

  1. May 25, 2016 #1
    1. The problem statement, all variables and given/known data

    in this question , Lm / Lp = 1/ 6 ? or Lp / Lm = 1/6 ? Lp = length of prototype , Lm = Length of model

    Mb4Cvh3.jpg

    2. Relevant equations


    3. The attempt at a solution
    i really have no idea... can someone help please?
     
  2. jcsd
  3. May 25, 2016 #2

    phinds

    User Avatar
    Gold Member

    If you have no idea at all then the question arises, how do you come to be working on a problem that you have no idea how to answer? What level of school are you in? Where is the problem from? We don't spoon-feed answers here, we try to help you solve a problem yourself, but we need more background to even be able to give you a hint that would be meaningful to you.
     
  4. May 25, 2016 #3
    i am in uni now , and the notes is from my book , IMO , it should be Lp / Lm = 1/6 , am i right ?
    can you help ?
     
  5. May 28, 2016 #4
    i dont think the working provided is correct
    IMO , it should be (Vr)( Lr )= (nu)r

    nu = kinematic viscosity
    since nu is constant , so ,

    Vp / Vm = Lm / Lp
    60 / Vm = 1/6

    so , Vm = 360km/h , am i right ?

    thus , force has formula of ρ(L^3)(velocity) , so force is directly proportional to v ,

    Fp / Fm = Vp / Vm
    Fp / 250 = 60/360 , Fp = 41.7N , is it correct ?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Loading...