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I need help with force/momentum/vectors

  1. Jul 3, 2005 #1
    I am asked to do this.

    "A uniform beam is attached to two springs scales as shown. The scales read 71 lb and 100 lb respectively. Find the wight of the beam."


    I have no idea how to go on about solving this. please someone explain it to me like you would explain it to a child.

    Thanks in advance.
  2. jcsd
  3. Jul 3, 2005 #2


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    I'm not being awkward, but I don't understand the diagram one bit.
  4. Jul 3, 2005 #3

    Meir Achuz

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    My guess is that the diagram is meant to show a rod held up by two strings,
    one at 45 degrees with a tensiion of 71#, and the other at 60 degrees from the horizontal with a tension of 100#. This is consistent with their being no net horizontal force on the rod.
    The net horizontal force is 100 cos 60 - 71 sin 45=0 (as it should).
    The net upward force on the stick is 100 sin 60 + 71 sin 45 =87 + 50 = 137#,
    which equals the weight of the stick.
  5. Jul 3, 2005 #4
    I reccomended him here for help guys, don't make me look bad:)

    That diagram IS funky though
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