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Homework Help: Free-fall gravity problem

  1. Feb 24, 2008 #1
    1. The problem statement, all variables and given/known data

    I have just a question to clarify. When an object is in free-fall the gravity is always + 9.81 m/s^2? and also when it is talking about two dimension kinematics gravity is working on an object thrown in the air it is -9.81 m/s^2?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Feb 24, 2008 #2
    Yes, when the object is in freefall on Earth, gravity = a = 9.8m/s^2 down. Signs are optional but you could say -9.8n/s^s.
    In 2D, the gravity is always 9.8m/s^2 down on the object.

    It doesn't matter how the object is moving or thrown, gravity is always down.
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