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Homework Help: Simple vector on a train drawing problem

  1. Oct 7, 2011 #1
    The problem statement, all vaA ball is hanging from a long string that is tied to the ceiling of a train car traveling eastward on horizontal tracks. An observer inside the train car sees the ball hang motionless.

    Draw a clearly labeled free-body diagram for the ball if the train has a uniform velocity.

    Draw a clearly labeled free-body diagram for the ball if the train is speeding up uniformly.

    -for the first one i drew two vectors. one up. one down with the same magnitude and mastering physics said it was wrong. i dont know why?
     
  2. jcsd
  3. Oct 7, 2011 #2

    PeterO

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    Homework Helper

    What labels did you use for those two forces? Perhaps that was the problem.
     
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