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Homework Help: Acceleration at incline with friction

  1. Sep 20, 2010 #1
    1. The problem statement, all variables and given/known data

    A block of mass 250 kg is placed at rest onto 5 different inclines. The angle of incline A is
    22o,
    B is at 22o,
    C is at 22o,
    D is at 10o, and
    E is at 10o.
    The inclines are made of different materials, and have coefficients of friction
    mkA = 0.3,
    mkB = 0.4,
    mkC = 0.5,
    mkD = 0.2, and
    mkE = 0.1.
    For each incline, the static friction is only marginally higher than the kinetic friction.
    Rank the magnitude of the acceleration of the block on each incline, from smallest to largest. For ties, list answers alphabetically.


    2. Relevant equations

    F=ma
    Frictional force equation

    3. The attempt at a solution

    I tried and got these values: A: .945224m/s^2
    B: .036584m/s^2
    C: -.872056m/s^2
    D: -.228472m/s^2
    and E: .73664m/s^2

    so I tried C,D,B,E,A but it was wrong :-(
     
  2. jcsd
  3. Sep 22, 2010 #2
    Try B again, it doesn't look like you've calculated it correctly.
     
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