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Homework Help: Force + work

  1. Dec 2, 2004 #1
    One question related to newton's third law,
    v
    t p
    u o
    u o
    It is a rope with a wheel,v.
    If 50N is applied from u pulling towards the ground, what's the reaction force?
    From o to p ?

    Two questions related to work,
    I think the force in the equation of work done is continuously applied,like weight, right?
    And the object would not stop finally, right?

    For the PE, a weight of 100N is lifted up by a man up to a height of 10m.
    Why the force applied by the man continuously is 100N?
    Isn't 100 N causing no effect on the weight as it is compensated by the mg of the weight, right?
     
  2. jcsd
  3. Dec 2, 2004 #2

    arildno

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    "One question related to newton's third law,
    v
    t p
    u o
    u o
    It is a rope with a wheel,v.
    "
    What does this mean???
     
  4. Dec 2, 2004 #3
    :confused: :confused:
     
  5. Dec 3, 2004 #4
    How about these?
    Two questions related to work,
    I think the force in the equation of work done is continuously applied,like weight, right?
    And the object would not stop finally, right?

    For the PE, a weight of 100N is lifted up by a man up to a height of 10m.
    Why the force applied by the man continuously is 100N?
    Isn't 100 N causing no effect on the weight as it is compensated by the mg of the weight, right?
     
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