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Homework Help: Friction problem

  1. Jan 10, 2007 #1

    srh

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    1. The problem statement, all variables and given/known data
    I have attached a picture. Determine the friction force acting on the block shown when the angle is 30 degrees and P=200 N.


    2. Relevant equations
    us=0.3 (static friction)
    uk=0.2 (kinetic friction)


    3. The attempt at a solution

    I set up a free-body diagram w/the 1kN, P, Normal force and frictional force. I was able to solve for both the Normal force and frictional force. I got 326.79N for friction and 966.025 for Normal. I thought I was incorrect because it doesn't fit into the f<=usN
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. Jan 11, 2007 #2

    Hootenanny

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    Staff Emeritus
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    Gold Member

    Perhaps if you showed your working, we could show you where you've gone wrong...
     
  4. Jan 11, 2007 #3
    I would draw a better diagram :).

    One with acceleration; in which direction is it pointing? Acceleration sets your positives/negatives on the axis on the diagram. The friction; in which way is friction pointing/acting?

    After doing such you can do a summination of forces =).
     
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