The First Law of Thermodynamics Derived?
The first law of thermodynamics generalizes the concept of energy conservation to include heat energy. You probably already appreciate that loss of total mechanical energy (e.g., from nonconservative forces such as friction) does not destroy energy, but rather converts mechanical energy to heat. This process can be described quantitatively by the first law. By relating heat, internal energy, and work, the first law lays the groundwork for thermodynamics, a field that also explains the conversion of heat into mechanical energy. Like the law of mechanical energy conservation that it generalizes, the first law relates the changes in energy that occur from the beginning to the end of some process. The first law involves changes in the following physical quantities: * dW: work done by the system on the outside world, * dQ: heat added to the system by the outside world, and * dU: internal energy change of the system. You need to look carefully at the wording used here; some other disciplines (chemistry comes to mind) may use other definitions. Part A Which of the following is the sign convention that results from these definitions? dW is positive when the system is compressed, and dQ is positive when heat is added to the system. dW is positive when the system expands, and dQ is positive when heat is added to the system. dW is positive when the system is compressed, and dQ is positive when heat is taken from the system. dW is positive when the system expands, and dQ is positive when heat is taken from the system. Part B Using your knowledge of energy conservation, express dQ in terms of dU and dW.
Could the first law of thermodynamics be wrong?
First - I'm not suggesting that it is! I just noted that the way that it is proven is by examining the amount of energy produced through work placed on an object, and measuring the output. But does such a process necessarily support the idea that "energy can neither be created nor destroyed"? I can see the link, but to draw such a conclusion from this experiment doesn't seem logical - could energy be created in the universe at random, and we've just not noticed it? After all, the big bang occurred somehow and this energy must have either come from somewhere or nowhere. Someone with some knowledge tell me why I'm dumb please. Many thanks.
What is the 1st law of thermodynamics?
The first law of thermodynamics is the application of the conservation of energy principle to heat and thermodynamic processes:The first law makes use of the key concepts of internal energy, heat, and system work. It is used extensively in the discussion of heat engines. The standard unit for all these quantities would be the joule, although they are sometimes expressed in calories or BTU.It is typical for chemistry texts to write the first law as ΔU=Q+W. It is the same law, of course - the thermodynamic expression of the conservation of energy principle. It is just that W is defined as the work done on the system instead of work done by the system. In the context of physics, the common scenario is one of adding heat to a volume of gas and using the expansion of that gas to do work, as in the pushing down of a piston in an internal combustion engine. In the context of chemical reactions and process, it may be more common to deal with situations where work is done on the system rather than by it.
Is the first law of thermodynamic universal?
If by universal you mean applies to the entire universe, then the answer is NO. The first law of thermo does not hold for the universe. One way is just how you describe, by creating more space out of nowhere and pushing the universe apart as a result of this newly create "free" energy. Where it comes from? Noone knows, similarly to how we don't know where all the energy for our current universe came from.The first law is "universal" for all closed systems, which is to say things smaller than our universe where energy is not being added or removed.
What is the first law of thermodynamics? Teach me like I'm 4 years old.
Congratulations, you just received a defined region of space called a “piggy bank” for your fourth birthday. If you put a quarter in your piggy bank, it will contain twenty five cents. If you put a dime in afterwards, it will contain thirty five cents. If you then remove the quarter to go buy some candy, you will be left with ten cents. Money is neither created nor destroyed (pipe down all you economists; remember, he's four), it can only go into the piggy bank or come out of it. You can take money out of the piggy bank to buy things. When the piggy bank is empty, you can't buy anything, because the amount of money you have is absolutely zero. This concept is known as conservation of money.The First Law of Thermodynamics is a statement of conservation of energy. A thermodynamic system is like a piggy bank, only its currency is energy (more specifically, heat and work). If you put twenty five Joules of energy (heat or work) into your thermodynamic piggy bank, it will contain exactly twenty five Joules of energy until you (or somebody else) takes it out. If you put in another ten Joules, you will have thirty five Joules at your disposal. If you use twenty five Joules of energy to do work, you will be left with ten Joules in the bank. Just like money, energy is neither created nor destroyed. It can only go into or out of a system. A system that contains some internal energy can be used to do work or heat some other object (according to the First Law anyway), but when the system has no more energy, it can't do any work or give up any heat because its temperature is at absolute zero.
What is the first law of thermodynamics? What is its significance?
The first law of thermodynamics tells us that the total energy of a system plus the surroundings remains constant, therefore, the energy is conserved.ΔEsist = ΔEsurrConsidering a stationary system and without the influence of external force fields, the energy of a system is equal to its internal energy:ΔUsist = ΔUsurrIn a closed system, the variation of the internal energy of a system is the result of the heat (q) flowing into the system and the work (w) performed upon it.ΔU = q + wFor an infinitesimal process in a closed system, dU = dq + dwIt is also considered that U is a function of state, meaning that it depends only on the initial and final states, ΔU = Uf − Ui.For the discussion of other concepts on thermodynamics, you can check my book: Short notes on thermodynamics and physical chemistry.
What are the implications of the First Law of Thermodynamics?
The first significance is related with law of conservation of energy, heat and work both are different forms of same entity known as energy which is conserved
What would happen if the first law of thermodynamics was disproved?
The First Law of Thermodynamics has been experimentally demonstrated in enough different places and to a high enough precision that any deviation would have to be new and unusual physics. In other words, we know the First Law works in almost every situation, so violations aren't going to be easy to find even if we know they are there. In much the same way that Newtonian Gravity and Galilean relativity weren't just thrown out the window after Einstein came along, it's unlikely that the First Law would be abandoned entirely. More than likely we'd teach it as a first step and then introduce this new physics as a perturbation on top of the First Law. It's been over a hundred years since special relativity was postulated and it's still not something that is intuitive to the general public. As for the impact, it would be two-fold. It would revolutionize physics in much the same way that relativity and quantum mechanics did. There would be lots of scientists that would first try to reproduce and then try to understand this new phenomenon. It might quickly lead to lots of new physics or it might lead to more confusion, but it would lead to a great deal of work and renewed interest. The second, assuming the discovery were economically viable, would be the societal aspects of essentially unlimited energy.
The first law of thermodynamics seems to conflict with what we know about ourselves.?
That energy has been lost as heat. We are converting the chemical energy derived from our food to the mechanical energy of our muscles. Thermodynamics says that anytime there is a conversion of energy from one form to another, some is always lost as heat (and is unusable). As we exercise, we produce a lot of heat, so we sweat in an attempt to cool off.