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

About thermodynamics laws

  1. Sep 9, 2007 #1
    1. i read all my notes about the thermodynamics laws and the second one was so interesting? As i found it opposes the first one so how ia that possible. If not just tell me the right thing.
    2. I've tried to make a diffenrence between the heat engines and the refrigerator: heat engines absorb heat and transform it( not completely) into work whereas refrigerators transorm work (with some few additional heat) into heat. But the problem is that i'm not conviced about the refrigeratorm, so i want someone else to make me sure.
  2. jcsd
  3. Sep 9, 2007 #2


    User Avatar

    Staff: Mentor

    You are correct. Refrigerators use mechanical work to move heat around, heat engines allow heat to move around to produce mechanical work.
  4. Sep 12, 2007 #3

    Shooting Star

    User Avatar
    Homework Helper

    You must have somehow misinterpreted your notes. The 1st law states that energy is conserved, and the second law states that the entropy of an isolated system not in equilibrium will increase, or tend to increase over time, approaching some maximum value at equilibrium. There is no ccontradiction whatsoever.
  5. Sep 12, 2007 #4
    Yeah entropy (A measure of disorder) will tend to increase, meaning that everything will get more disordered as time progesses. Solids (Very ordered), Liquids (Disordered) and gases (Very disordered).
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?