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

I What does this symbol represent?

  1. Feb 9, 2017 #1
    In my nuclear engineering class we are looking at relativity right now. For one of our homework problems we have to derive an equation for a particle moving at relativistic speed showing the kinetic energy in terms of the particles momentum. In the answer they have a term mc and I have no idea what this represents. I can't find it in the book or online. I was wondering if somebody maybe knew what it meant?
     
  2. jcsd
  3. Feb 9, 2017 #2

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Without proper context it is not possible to answer your question. Are we supposed to guess what the answer looks like and where this symbol appears?
     
  4. Feb 9, 2017 #3
    The answer is:
    T = (p2c2+mo2c4)1/2-mcc2
    I know:
    p = momentum
    T = Kinetic Energy
    c = speed of light
    mo = Rest mass​

    I'm just confused on what mc represents.
     
  5. Feb 10, 2017 #4

    jtbell

    User Avatar

    Staff: Mentor

    I think that's just a typographical error, and ##m_c## should really be ##m_0## (the "rest mass", which also appears inside the parentheses). Or even a mechanical printing flaw that turned an "0" into a "c".
     
  6. Feb 10, 2017 #5

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Based on the expression, it has to be m0. The expression subtracts the rest energy from the total energy.
     
  7. Feb 10, 2017 #6

    ChrisVer

    User Avatar
    Gold Member

    As everyone mentioned above, this is a typo and was meant to be m0 (rest mass).
    On the LHS of the equation you have T which is the "kinetic energy"... the kinetic energy would be equal to the total energy of your particle (E) minus the rest mass energy it has even when it's at rest (the m0).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted