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Tension in a system

  1. Oct 27, 2015 #1
    1. The problem statement, all variables and given/known data
    Isn’t this question same concept as the note as I posted ? I found

    P = T + F1+F2= 50(0.3)(9.81) + 50(0.3)(9.81) + (50+100)(0.35)(9.81) = 809.3N

    But the ans given is 662.2 N ..

    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Oct 27, 2015 #2


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    Draw the FBD for block B alone. What are the forces acting on block B? Does T act on block B?
  4. Oct 28, 2015 #3

    Attached Files:

  5. Oct 28, 2015 #4


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    The question for which the given answer is 662.2N does not have a pulley nor a rope attached to the right of B. Why did you add those to the diagram?
  6. Oct 28, 2015 #5
  7. Oct 28, 2015 #6


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    In the first post of this thread, you attached two problem statements as images.
    The first one is a copy the question in the earlier thread. This has the two blocks connected via a string which passes around a pulley (not shown) attached to a wall. Another string pulls on the lower block.
    The second image shows the top block tied to a wall. Only one string attaches to the lower block, and there is no pulley. You appear to have drawn in a second string, making it look like the first problem. The two problems are different. If you modify it to look like the first problem then of course you will get the wrong answer.
  8. Oct 29, 2015 #7
    ok , noticed my mistakes
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