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!

Tension in a cord with Vectors, getting started

  1. Oct 11, 2007 #1

    lim

    User Avatar

    1. The problem statement, all variables and given/known data

    [​IMG]
    Find the tension in cord 2, shown in figure below. Neglect the mass of the cords, and assume that the angle q(theta) is 29.7 ° and the mass m is 190 kg.

    Find the tension in cord 1.

    2. Relevant equations

    T2CosQ2 - T1cosQ1= 0
    T1SinQ1 + T2SinQ2 - m(g)=0

    3. The attempt at a solution

    Isn't there a AIA angle property that would make the angle opposite and adjacent to theta( 29.7) equal to it, and that would be Q2(the angle for cord 2).

    So
    cord 2 = T2Cos(29.7) - T1cosQ1= 0, but how do I find the angle for cord 1? I can't assume that it's 90 degrees.

    Helpp
     
  2. jcsd
  3. Oct 11, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    It looks like cord 1 is horizontal. That's what I would assume.
     
  4. Oct 11, 2007 #3

    lim

    User Avatar

    so for cord 2 I did T2CosQ2 - T1cosQ1= 0
    T2 Cos(29.7) - T1 Cos(90) = 0
    T2 .868 -0= 0
    T2 = 0.868?
     
  5. Oct 11, 2007 #4

    Doc Al

    User Avatar

    Staff: Mentor

    No. Cord 1 is horizontal, so its angle with the x-axis is 0, not 90.
     
  6. Oct 11, 2007 #5

    lim

    User Avatar

    T2 Cos(29.7) - T1 Cos(0) = 0
    T2 (.868) - T1 (1)= 0
    T2 - 0.132= 0
    T2 = .132
    What else did I miss? My answer isn't right.
     
  7. Oct 11, 2007 #6

    Doc Al

    User Avatar

    Staff: Mentor

    So far, so good.
    These steps are mathematically incorrect. The proper next step is:
    T2 (.868) = T1

    You need to combine this with the equation for vertical forces. You'll get two equations and two unknowns.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Tension in a cord with Vectors, getting started
  1. Tension of a cord (Replies: 0)

  2. Tension in Cord (Replies: 1)

  3. Tension of the cord (Replies: 2)

  4. Tension of a cord (Replies: 3)

  5. Tension in cord. (Replies: 9)

Loading...