Introduction to Thermodynamics Introduction Thermodynamics
E this l Article , allows a first approach to the study of thermodynamics in a simple way compared to a game where everyone is participating , knowing you can not win ever. "Reading is a readiness to go after a more formal study.
We must make a careful reading and understanding, discuss, reflect with your fellow group and then answer the questionnaire t or notebook, and present the findings to your class teacher. Some hyperlinks have been left for consulting and expand the concepts basic.
The game of thermodynamics
is considered that the Laws of Thermodynamics laws are "more categories" of all physics, and thus all of science. Are the most tested of all science, and are considered authentic pillars of physics. If they ever prove wrong, all our modern science would be shaken.
And yet, despite their importance, are less known by "ordinary people" than others, as Universal Law of Gravitation , or Accióny Act reaction (Third Law Newton). Well, in today's article we will review them using a fun way to remember (a formulation known humorous of the three classical laws of thermodynamics, the origin unaware).
First Law
The First Law of Thermodynamics , in fact it is well known by the general public, and possibly the law physical best known for worldwide. It is the law of conservation of energy, which can be stated thus: "Energy is neither created nor destroyed, only transformed."
Its formal statement is different, but the idea behind that is. In any action we can imagine, the power game is always the same. If we win power, should be at the expense of something or someone, and if we lose, you go somewhere. We can not get energy from nothing, or as the saying goes, "where there is not, can not be removed."
For centuries, inventors of all types have tried to find what is called " perpetual motion machine of the first kind": a machine that produces more energy it consumes. But as we see, that's impossible. The First Law prevents us.
In the game of thermodynamics, simply can not win.
Second Law
The Second Law of Thermodynamics is somewhat less known and more "cryptic." It may sound like any man's law "that rarest of entropy." In fact, the most common enunciation of the Second Law tells us that the entropy of a system (closed and is not in equilibrium), tends to increase with time until equilibrium is reached.
What does that mean? What is that of entropy? Well, we can define entropy as "usable energy" to do a job. Ie an energy that is there, but we can not use. And how is that? Now, any object in the universe, by the mere fact of being at a temperature above the absolute zero (0 K) has an internal energy we call heat (actually, being purists, the heat is the transfer of the internal energy, but for now we need not be so precise). But to take the heat, the object must be able to transfer it to another. And for that to happen, the second object must have a lower temperature.
This is very easy to understand if we consider the following: imagine we have a pitcher of warm milk, and another of cold milk. If we mix two liquids, cold milk is heated, hot and cold, until we have all the milk at the same temperature. However, if we return to separate the milk into two jars, never, never, ever, one was cool at the expense of the other (which would be heated), naturally. By mixing the two milk jugs, we have made an irreversible process. If we return to a temperature difference between the pitchers will need an external power source to "pump" heat from one another.
So we think that the Second Law says that heat flows naturally from the bodies of higher temperature, the less. And if we reverse this process, need to apply energy. That's why air conditioners and refrigerators consume energy, despite extracting heat (energy) from other objects, because that is not usable heat extracted.
One consequence of this law (and thus defined by Lord Kelvin), we can not convert 100% of the heat into usable energy. Or what is the same, no energy transformation process, 100% efficient. Throughout the process, lose some energy as heat, to be used to raise the temperature of any component of your machine, or environment, and we can not take advantage.
For centuries, inventors have tried also to find a way to transform energy with an efficiency of 100%. But that would be a "perpetual motion machine of second kind", something less ambitious than the first kind, but also impossible, because the Second Law prevents us.
In the game of thermodynamics, you can not draw.
Third Law
The Third Law of Thermodynamics , yes it is a "great unknown" for public in general. Is 'the other', the George Harrison of thermodynamics. And yet it is essential, allowing us to define absolute temperature scale. Basically tells us it is impossible to reach a temperature of 0 K (absolute zero) in a finite number of processes, which in practice means that it is impossible to reach that temperature.
That means that all objects in the universe has a temperature above 0 K, so that all objects in the universe, have some heat, even slightly. And therefore, no leaks of thermodynamics.
In the game of thermodynamics, not even you leave.
"Ceroésima" Act
A Zeroth Law of Thermodynamics . This unusual name is because it is much more basic than the others, but was stated quite later (we had a First Law). He says that two systems are in thermodynamic equilibrium with a third party, are in balance. It may seem a truism, but it must state it formally.
Tyranny thermodynamics
If we stay with the three classical laws of thermodynamics, we have a game where you never want ; owners to participate, if we had the choice:
can not win.
can not match.
can not leave.
So that we can only lose. And certainly, if the universe lasted long enough, come a time in which all particles would be at the same temperature, and it would be impossible for any thermodynamic process. This is what is known as the Heat Death of the Universe.
But we can not choose. Is the game in which we play and we can not change its rules.
Quiz: resolve by reference to the article read.
1. The first law of thermodynamics relates to the principle of conservation of energy:
a. enunciates the principle of conservation of energy.
b. Speak with your own words the first law of thermodynamics (With reference to the article read)
c. 's reading: What is the "perpetual motion machine?
d. Under the first law of thermodynamics: Why is it impossible to create a "perpetual motion machine?
E.
explains the term related to the first law of thermodynamics: " In the game of thermodynamics, simply You can not win. "
2. The second law of thermodynamics is related to the entropy.
a. According to the article: What is meant by entropy?
b. What is heat?
c. What is meant by absolute zero?
d. know that energy can be transformed into work. What explains the second law of thermodynamics?
e. What is the difference between "perpetual motion machine" and " perpetual motion machine the second kind ", as read?
f. explains the term related to the second law of thermodynamics: " In game thermodynamics, you can not draw. "
3. What explains the third law of thermodynamics?
a. What temperature scales you know?
b. explains the term connected with the third law of thermodynamics: " In the game of thermodynamics, not even you leave. "
4. What explains the zeroth law of thermodynamics?
a. Why do you think that article is called "Ceroésima" law?
B. Why talk about " T Iranian thermodynamics " (in the article)?
5. For scientists: What is meant by " Thermal Death Universe ? Do you think this would be the end of the world according to physics? Why?
The Teaching your class,
Joseph Wilson