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Homework Help: Suppose B is moving with speed v away from A

  1. Nov 12, 2012 #1
    1. The problem statement, all variables and given/known data


    Hi guys, i have a very simple question here about K-calculus.

    Suppose B is moving with speed v away from A.

    At time = t, an explosion (event) occurs in A, sending light in all directions.

    2dgs4e9.png


    According to the K-Calculus,

    The time the explosion occured in B would be:

    t' = kt


    But, using lorentz transformations:

    t' = γ(t - vx/c2)

    Since x = 0,

    t' = γt


    But it is quite clear that k≠γ..
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution


    Nevermind, I have solved it:

    Time light from event received by B ≠ Time of event

    Bu rather, the observer takes into account and B compensates for the time needed for light from the event to travel to him:

    t' = kt - (v/c)t'

    t' = kt/(1 + β) = γt (Shown)
     
  2. jcsd
  3. Nov 12, 2012 #2
    Re: K-calculus

    Also on a side note, is it possible to prove the K-calculus using geometry? Which basically says that 'u' length along the ct axis would translate into 'k*u' length along the ct' axis..
     
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