1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Confusion about 2nd law of thermo

  1. Feb 25, 2016 #1
    Entropy has units of kJ/kg K and energy has units of kJ. So my question is if entropy is not conserved how is energy conserved when there is a unit of energy within entropy?
  2. jcsd
  3. Feb 25, 2016 #2
    Hi nate:

    In a system in which entropy increases, there will be another form of energy in the system which is decreasing so that the total energy is conserved. Generally this will be free energy, but AFAIK there technically might possibly be another category of energy other than "free energy" which would decrease as entropy increased.
    See https://en.wikipedia.org/wiki/Free_energy .

  4. Feb 25, 2016 #3
    If you have 90 lb of beef at $5/lb, the value of the beef is $450. Now the price goes up to $10/lb, and the value increases to $900. How come, if the value of the beef contains the mass of the beef as a factor, and mass is conserved, why isn't the value of the beef conserved?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook