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Homework Help: Why is weight positive if gravity is negative?

  1. Oct 10, 2012 #1
    1. The problem statement, all variables and given/known data
    Why is weight positive if gravity is negative?

    2. Relevant equations
    W = mg

    3. The attempt at a solution
    So say there is some weight of an object, and the object's mass is multiplied by the acceleration due to gravity pointing downwards, so the weight becomes negative when the positive mass is multiplied by a negative acceleration. Weight should then be negative, but why is weight always positive?
  2. jcsd
  3. Oct 10, 2012 #2

    Doc Al

    User Avatar

    Staff: Mentor

    W = mg just gives the magnitude of the weight, which is positive. The direction of the weight vector is downward. (Note that g is a positive constant.) Often when you talk about the weight of something you just mean the magnitude.
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