The three laws of thermodynamics?

Question

Can someone briefly explain in their own words the three laws of thermodynamics, basic principles, just the main gist of it with a small example.

Cheers guys thanks!

Answer 1

Thermodynamics is the study of the inter-relation between heat, work and internal energy of a system.

The British scientist and author C.P. Snow had an excellent way of remembering the three laws:

1.You cannot win (that is, you cannot get something for nothing, because matter and energy are conserved).


2.You cannot break even (you cannot return to the same energy state, because there is always an increase in disorder; entropy always increases).


3.You cannot get out of the game (because absolute zero is unattainable).

"Answered by: Dan Summons, Physics Undergrad Student, UOS, Souhampton "

Answer 2

First Law: Energy is neither created nor destroyed. Simply put, all energy can do is change form, between heat and work in the most common sense. The implication is that there cannot be a perpetual motion machine.

Second Law: There exists a property of the Universe and parts of it called entropy. Think of entropy as a function of the amount of chaos in a system. The total amount of entropy is always increasing. What this means is that eventually all of the energy in the form of work will wind up as heat. Simply put, no machine is perfectly efficient.

Third Law: It is impossible to reach absolute zero temperature in a finite number of steps. What this does is define temperature in an absolute sense, with the minimum being 0 kelvins, or -273.15 degrees Celsius. Also, even though this point exists, it is not possible to get to it (although scientists have gotten close).

Hope this helps.

Answer 3

1.In any process, the total energy of the universe remains constant.
2.There is no process that, operating in cycle, produces no other effect than the subtraction of a positive amount of heat from a reservoir and the production of an equal amount of work.
3.As temperature approaches absolute zero, the entropy of a system approaches a constant.

Answer 4

1) Energy is conserved

2) Entropy of any system always increases

3) Absolute zero is cold

Answer 5

first: energy is conserved in any process
second: entropy of the universe rises in any process
third: zero kelvin is utterly unattainable