1. Not finding help here? Sign up for a free 30min 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!

Statics: Belt friction

  1. Aug 11, 2013 #1
    1. The problem statement, all variables and given/known data
    ldTF3WW.png


    2. Relevant equations
    T1/T2=eμs
    where T2 is the larger tension and β is the angle between the tensions.


    3. The attempt at a solution

    Isolating each pipe:
    mdTTSvk.png
    W1 = 50*9.81 = 490.5N
    For pipe B, β = (2π)/3
    For pipe C, β = π/3

    For pipe B, T2 = 490.5N, so I have:
    490.5/T = e0.25*((2π)/3)
    T = 290.6N

    Now here is where I made the wrong choice. On pipe C, I chose W2 to be T2 because if equilibrium is maintained, it would make sense for W2 to be going down, not up. This got me the wrong answer.

    Then I tried making T2 = T instead:
    290.6/W2 = e0.25*(π/3)
    W2 = 233.7N
    m = 233.7/9.81 = 22.8kg

    22.8kg is the right answer. I am just not understanding why T is the stronger tension on pipe C. It seems to me that it would cause the 50kg weight to start falling.
     
  2. jcsd
  3. Aug 11, 2013 #2

    Delphi51

    User Avatar
    Homework Helper

    You mean as in the 290.6 N outbalancing the 233.7 N?
    The friction force helps the weaker force to hold the balance.
     
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: Statics: Belt friction
Loading...