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Mechanics problem

  1. Nov 26, 2015 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations
    Now i was wondering which friction would come into play for the inner object

    3. The attempt at a solution
    I tried putting in equations i know

    Σ μℕ = μ1f + μ2 f

    Am i right. I don't think i am because the values i get after solving it are wrong

    I would be glad to share more
  2. jcsd
  3. Nov 26, 2015 #2


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    Draw a separate free body diagram for each block. Which way are the forces on the block adjacent to the wall?
  4. Nov 26, 2015 #3
    So is this right

    Attached Files:

  5. Nov 26, 2015 #4
    No, do not add the forces, draw a free body diagram for each body individually. For example, draw body A and then show all the forces on it, including the gravitational force, frictional force on left side (with the wall) and frictional force on the right side (with the body B). Then solve for equilibrium.
  6. Nov 26, 2015 #5
    Sorry i don't understand. I don't get it the addition forces can u explain(please bear with i just entered high school)
  7. Nov 26, 2015 #6


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    When one body exerts a force on another, there is an equal and opposite reaction.
    Which forces operate where the two blocks meet? For each such force, there should be force one way in one diagram and an equal and opposite force in the other diagram.
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