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Length contractions affect on mass

  1. Dec 28, 2013 #1
    If an object is going at near C(light velocity) and undergoes length contraction. Does the mass fluctuate?I apologize if it is an obvious question but I'm a little rusty on my physics.
  2. jcsd
  3. Dec 28, 2013 #2


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    This is more a matter of convention than a matter of fact. The older convention was to say that mass would go up by a factor of gamma: http://en.wikipedia.org/wiki/Relativistic_mass#Relativistic_mass In that convention, momentum was still p=mv. Since about 1950, relativists have no longer used that convention. They take mass to be invariant and write [itex]p=m\gamma v[/itex]. Either way, it's not an effect caused by length contraction.
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