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Homework Help: Finding Center-of-Momentum Frame

  1. Nov 5, 2006 #1
    My prof has assigned several homework sets dealing with finding the relativistic cm frame for two particles. However, he has not been quite up to speed with grading them, so I don't know if I really have a clue what I'm doing, and he hasn't gone over it much in class. I can't seem to glean much from A.P. French about the specific method for finding this frame.

    I understand that it would be logical to use energy conservation to solve this problem. But I can't seem to find a systematic method for what should be a simple procedure.

    Could someone give me a quick walkthrough on the simplest procedure for doing this? I just want to find out if I'm doing something wrong BEFORE I get these homeworks back.

    Thanks much,
  2. jcsd
  3. Nov 6, 2006 #2


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    Here are a couple of references worth looking at, but you probably already have similar things in your text or notes. They are geared toward solving collision problems. In the most general case, you could have two particles with arbitrary momenta. You still have a total momentum as the sum of the two initial momenta, and the velocity of the center of momentum can be calculated from momentum and energy.

    http://physics.nmt.edu/~raymond/classes/ph13xbook/node107.html#elasticenergy [Broken]


    Maybe if you posted specific problems with your attempted solutions someone could help you in more detail.
    Last edited by a moderator: May 2, 2017
  4. Nov 6, 2006 #3

    Thanks a million for those links! The explanation was much more comprehensive and sequential than the one that my prof gave...or rather didn't give.

    You're my savior, man!

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