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How do i convert ?

  1. Jun 21, 2005 #1
    I was reading a book on the theory of relativity yesterday and it said that by substituting the equation for momentum (p=mv) in to the formula E^2=m^2c^4+p^2c^2..
    i will be able to get this E=gamma mc^2..
    I was just wondering where they get the "gamma" from? :confused: can anyone pls tell me how they get that? Thx
    sry, not really good at this. :cry:
  2. jcsd
  3. Jun 21, 2005 #2


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    gamme is equal to 1 over the square root of 1-((v^2)/(c^2))
  4. Jun 21, 2005 #3


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    You need to be careful with the notation.

    [tex] E^{2}=m^{2}c^{4}+p^{2}c^{2} [/tex]

    and [tex] p=\gamma m v [/tex].

  5. Jun 21, 2005 #4
    Isn't momentum=mass x velocity?
  6. Jun 21, 2005 #5


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    Not in relativistic physics. Its gamma * mass * velocity as v -> c
  7. Jun 21, 2005 #6
    erm.. can we put velocity, v, and speed of light, c, together?
    eg: [tex] v^{2}c^{2}=c^{4} [/tex]
    Last edited: Jun 21, 2005
  8. Jun 21, 2005 #7
    but it sounds ridiculous rite? how can the velocity be equal to the speed of light?
  9. Jun 21, 2005 #8
    k.. guys, i get it alr..thx thx so much!
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