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Homework Help: Coefficient of friction help please!

  1. Nov 21, 2008 #1
    1. The problem statement, all variables and given/known data

    A train moves on a straight track at y degrees to the horizontal. The mass of the train is 1000kg. during its motion the train moves under the action of a variable propulsive force, p newtons, and a constant resultant forceR newtons

    (a) during the first stage of motion, the train moves horizontally with acceleration 0.25 ms-2. In this stage the value of P is 1200 sow that R = 950.

    2. Relevant equations

    F=ma mabey

    3. The attempt at a solution

    resolved the force in direction of train got;

    1200 - R - sinyo = 1000 x 0.25
    950 = R + sinyo

    so how can R = 950, is sinyo taken as < 0.5??
    help please!
  2. jcsd
  3. Nov 21, 2008 #2
    In part (a) of the question, when it says the train is moving horizontally, it means that y=0o.
  4. Nov 21, 2008 #3
    aaaaah you ledgend, cannot believe i didnt see that - i really am a physics goon!
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