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Homework Help: Differentiating Lorentz factor with respect to time

  1. Jan 29, 2007 #1
    1. The problem statement, all variables and given/known data
    I would like some help on differentiating the lorentz factor with respect to time

    2. Relevant equations

    3. The attempt at a solution

    i arrived at [tex] (-1/2) (1-v^2/c^2)^{-3/2} [/tex]
    but a forum on this website says it is [tex] (-1/2) (1-v^2/c^2)^{-3/2} ( \frac{-2v}{c^2} dv/dt)[/tex]

    Please help!
  2. jcsd
  3. Jan 29, 2007 #2


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    You want [tex]\frac{d}{dt}(1-v^2/c^2)^{-1/2}[/tex]. Using the chain rule, this is equal to [tex] \frac{d}{dv}(1-v^2/c^2)^{-1/2}\frac{dv}{dt}=\left(\frac{-1}{2}\right)\left(\frac{-2v}{c^2}\right)(1-v^2/c^2)^{-3/2}\frac{dv}{dt}[/tex]

    Does that help?
  4. Jan 29, 2007 #3
    Thnx a ton cristo!Just cudnt think about it
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