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Homework Help: Simple elastic particle problem

  1. Mar 14, 2008 #1
    1. The problem statement, all variables and given/known data

    A 61.9kg object moving to the right at 43.3 cm/s overtakes and collides elastically with a second 44.9kg object moving in the same direction at 26.9cm/s

    Find the velocity of the second object after the collision.

    2. Relevant equations
    My hw says its in the chapter and section with "velocity of the center of mass" and "momentum in terms of velocity of CM" But I think its wrong and I should be looking at the elastic collision chapter.

    3. The attempt at a solution

    I tried doing conservation of momentum but I don't know the velocity of object 1 after collision.
    I tried using the elastic collision equations but those use one mass having a velocity of 0.

    I pretty much confused where to start.
  2. jcsd
  3. Mar 14, 2008 #2


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    Homework Helper

    Use the conservation of linear momentum with the two unknown final velocities.
    and then remember that in an elastic collision, kinetic energy is conserved and you can now find the two values for the final velocities.
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