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Homework Help: Showing px-Et is invariant using Lorentz Transformations

  1. Feb 2, 2009 #1
    1. Using the Lorentz Transformations, show that the quantity px - Et is invariant, where p and E are the momentum and energy, respectively, of an object at position x at time t.



    2. px - Et



    3. I needed help on starting the problem. Where should I begin?
     
  2. jcsd
  3. Feb 2, 2009 #2

    tiny-tim

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    Hi Nitric! :smile:

    Hint: what 4-vectors can you see in this problem? :wink:
     
  4. Feb 2, 2009 #3
    Re: Invariance

    p x E and t?
     
  5. Feb 2, 2009 #4

    tiny-tim

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    erm … nooo :redface:
     
  6. Feb 2, 2009 #5
    Re: Invariance

    Damn. Well I honestly have no idea, kinda stuck on this problem
     
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