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Homework Help: Help Needed - Two bodies, inclined plane, some friction, and pulley problem!

  1. Oct 14, 2009 #1
    1. The problem statement, all variables and given/known data
    Block A has mass m = 4.0 kg, and block B has mass m= 2.0 kg. The coefficient of kinetic friction between block B and the horizontal plane is 0.50. The inclined plane is frictionless at the angle 30 degrees and Block A sits on it. The pulley serves only to change the direction of the cord connecting the blocks. The cord has negligible mass. Find (a) the tension in the cord and (b) the magnitude of the acceleration of the blocks.

    2. Relevant equations
    FN = Fgx
    Fg = mg
    a = Fnet/m

    3. The attempt at a solution
    I found the normal force of block A to be 33.95 N and the Fg to be 39.2 N. For block B, FN should be 19.6 N and fk should be 9.8 N.

    Now I'm just confused about what forces cause the tension force (I don't know what to add, subtract, etc. to get FT)

    I need help tonight if possible!
  2. jcsd
  3. Oct 14, 2009 #2


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    Homework Helper

    Take the components of mg along the inclined plane. It is in the downward direction. Find the net force acting on it.
    Then the acceleration of the sliding body. Equate it to that of the body on the table.
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