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!

String tension

  1. May 9, 2004 #1
    Two strings are attached to a 5 kg mass. String one is at a 45 degree angle and the other is horizontal. What is the tension in string one?
  2. jcsd
  3. May 9, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    From my reading of this, String one is the only one capable of counteracting the weight of the mass (since it alone has a vertical component).

    The tension in string one (i.e magnitude of tensile force) should therefore be:
  4. May 9, 2004 #3
    where did the sqrt(2) come from?

    your equation works but how did you get it?
  5. May 9, 2004 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Assume that string one goes along the line (-cos(45),sin(45)), wheras string two is along the horizontal (1,0) (The mass itself is position at the origin).

    (Clearly, the only necessary requirement is that the tensile force in string one has a component in the positive vertical component, in order to balance the weight of the mass).
  6. May 14, 2004 #5
    T1 = 63.9N
    T2 = 49N

    I just resolved horizontally and vertically
    T1sin45 = 5G
    Simplification gives T1 = 63.9N

    Calculating T2 is optional, but i got 49N.
  7. May 14, 2004 #6
    To be sure, is the above correct? I'm revising for my mathematics - mechanics exam and that seems to be similar to a few of the questions.
  8. May 14, 2004 #7
    Yes that's correct KnowledgeIsPower.

    ΣFx = 0 = T2 - T1cos 45o
    ΣFy = 0 = T1sin 45o - mg

    From the second equation you can find T1, and the first will give you T2.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: String tension
  1. Tension of a String (Replies: 2)

  2. String Tension? (Replies: 2)

  3. Tension in strings (Replies: 18)

  4. Tension in string (Replies: 12)