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Kinetic Energy/Momentum

  1. Dec 9, 2006 #1
    An empty ore car coasts at a constant horizontal speed under an ore chute. Ore falls vertically into the car. What effect does the addition of the ore have on
    (a) The kinetic energy of the loaded car? The book says the answer is the same as the unloaded car.

    (b) The momentum of the loaded car? The book says: The ratio of the velocities is equal to the sqare root of the inverse ratio of the masses.

    So there is more momentum but not more kinetic energy?
  2. jcsd
  3. Dec 9, 2006 #2
    What is and "ore" ???

    HINT : check out the directions of the vectors in your question.

    For example for (a) : the kinetic energy depends on mass and velocity. Mass stays the same and your velocity vector is horizontal because the car moves horizontally. So, given the fact that the velocity vector remains horizontal, how would it change even if some object falls on the car along the vertical direction ?

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