How Many Laws of Thermodynamics Are There?

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SUMMARY

The discussion clarifies that there are four laws of thermodynamics, including the 0th law, which states that if system C is in thermal equilibrium with systems A and B, then A and B are also in thermal equilibrium. The 1st law defines the conservation of energy as the relationship between heat, change in internal energy, and work done on the system. The 2nd law asserts that entropy always increases over time, while the 3rd law states that no object can reach absolute zero. Participants also noted the implications of the 3rd law concerning the Heisenberg Uncertainty Principle (HUP).

PREREQUISITES
  • Understanding of basic thermodynamic concepts
  • Familiarity with the laws of thermodynamics
  • Knowledge of the Heisenberg Uncertainty Principle (HUP)
  • Basic physics principles related to energy and entropy
NEXT STEPS
  • Research the implications of the 0th law of thermodynamics
  • Study the conservation of energy as described in the 1st law
  • Explore the concept of entropy and its applications in the 2nd law
  • Investigate the Heisenberg Uncertainty Principle in relation to the 3rd law
USEFUL FOR

Students studying physics, educators teaching thermodynamics, and anyone interested in the foundational principles of energy and entropy in physical systems.

LENIN
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How many laws of thermodinamics are there?

This topic came up during one of our last hours of higschool physics. Some of us sead that there are 4 and some sead that there are only 2. In different books we also found different answeres. So now I really don't know which statement is corect. Any ideas?
 
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0th law - If a system, C is in thermal equilibrium with two other systems, A and B, then A and B must also be in thermal equilibrium.

1st law - Heat = Change in Internal Energy + Work done on the system. (Conservation of energy effectively).

2nd law - Entropy always increases with time.

3rd law - No object can ever reach a temperature of absolute zero.

A nice discussion of laws 1-3 can be found here.
http://www.physlink.com/Education/AskExperts/ae280.cfm

Claude.
 
1st Law: You can't win; you can only break even

2nd Law: You can only break even if you get to absolute zero.

3rd Law: You can't get to absolute zero.
 
rdt2 said:
1st Law: You can't win; you can only break even

2nd Law: You can only break even if you get to absolute zero.

3rd Law: You can't get to absolute zero.

you are forgetting a law here, see the above post

marlon
 
But i don't know why we can not reach the zero absolute temperature. Who can explain?
 
Essentially, because a particle at 0K violates the HUP. Google the 3rd law of thermodynamics and you should find some satisfying explanations.

Claude.
 

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