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Tension in a single rope holding a block, no motion.

  1. Dec 7, 2011 #1
    So this is a very basic question on tension, i assume, however every example provided in my book shows the tension within two cords. I can't seem to grasp the correct way to do this...

    The problem statement, all variables and given/known data

    A 2 kg block is suspended from a single rope. A horizontal force keeps the cord at 37o from the vertical. Find the module
    a) of the force
    b) the tension of the string

    2. Relevant equations
    Fg = 2*9,8 = 19,6 N
    uhmmm... stuck!

    3. The attempt at a solution
    I haven'y started the question because i need a boost, can anyone provide help?
  2. jcsd
  3. Dec 7, 2011 #2


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    Well, I'd start out by trying to balance the forces - if the block isn't moving, the forces you're interested in must be balanced by the gravitational force downwards, namely, the relevant equation above.

    (This is the first time I've tried to give homework help, if it's too much or too little information, do let me know!)
  4. Dec 7, 2011 #3
    So, seeing as the string is being pulled by a horizontal force, there's an angle at play. I imagine i should calculate the tension or force but I don't know what equations to use
  5. Dec 7, 2011 #4


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    To be honest, I'm a little bit confused about the source of this horizontal force, and wondering what's balancing it.

    Nevertheless -

    In a simpler situation, consider a block suspended from a rope, without moving, hanging straight down. Do you know how to calculate the tension in that situation?
  6. Dec 8, 2011 #5
    i figure the tension would be the same as the gravitational force, which is 19,6N, right?
  7. Dec 8, 2011 #6


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    So now, instead of just balancing the downwards force of gravity, you need to also balance the sideways force. What force would you need to keep the block at that angle?

    Sorry. I'm trying not to give it totally away.
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