Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

About Relativistic Mass-Energy Equivalence

  1. Oct 13, 2012 #1
    While I was looking up E=mc[itex]^{2}[/itex], I have learned such formula only applies to stationary objects and for kinetic object, the formula is this:
    Where E[itex]_{r}[/itex] is relativistic energy
    and m[itex]_{0}[/itex] is rest mass

    In the formula, what is p and what is (pc)[itex]^{2}[/itex]?
    Also, does the relativistic energy calculated here becomes relativistic mass of the object using E=mc[itex]^{2}[/itex]?
  2. jcsd
  3. Oct 13, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The symbol p is momentum.

    Here E is called the mass-energy of the object, and m is simply called its mass. The interpretation of [itex]E=mc^{2}[/itex] is that when the object is not moving (has zero momentum), the only mass-energy it has is the mass-energy due to its mass.

    The term "relativistic mass" is not used any more. Back when people used to use it, it meant the mass multiplied by a factor of [itex]\gamma[/itex].
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook