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Homework Help: Tension on a wire with equal angles

  1. Oct 8, 2008 #1
    1. A 100N light is suspended from a beam with two wires. Both wires make angles of 40 degrees with the beam.

    2. What is the tension in the wires?

    3. Ok heres what I have so far...
    Sum Fx: T2(cos 40)-T1(cos 40)=0
    so T2=T1

    Sum Fy: T2 (sin 40)+T1(sin 40+(-100)=0
    so T2(sin 40)+T1(sin 40)=100

    With subsitutions...
    T1(sin 40)+T1(sin 40)=100

    And T1=77.8N, T2=77.8N, and T3=100N
    Is this correct? And does changing the angle change the final breakdown? Such as if the angle was 30 degrees vice 40 degrees??
  2. jcsd
  3. Oct 8, 2008 #2
    That looks correct to me. If the angles both changed to 30 degrees, the equations would be exactly the same, except the tensions would have different numerical answers compared to if the angles were 40 degrees. This is because there is a smaller y component of tension.
  4. Oct 9, 2008 #3
    Thank you !! This has been getting me for about 2 weeks now.
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