Understanding Internal Energy: Path Dependence and Point Functions

In summary, the conversation discusses the concept of internal energy and its uniqueness as a function of state. The speaker points out that the change in internal energy only depends on the initial and final states, and not on the path. They also mention that the internal energy is not a unique function of state properties and can only be measured in terms of changes. The speaker also mentions a book they are using for their studies and expresses gratitude for the help provided.
  • #1
Amith2006
427
2
Sir,
I have a doubt. The internal energy U is a unique function of any state because change in U ___________. I think the answer is internal energy U is a unique function of any state because change in U does not depend upon path.U is a point function. But the given in book is " U depends upon path". Please clear this doubt.
 
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  • #2
You're absolutely right.

The change in the internal energy depends only on the inital and final states and does not depend on the path.

Also, the internal energy isn't even a unique function of the state properties. We can never measure the absolute internal energy of a state. We can only measure the changes in internal energy. So the question is doubly wrong.

What book are you using? I'm suprised that there is such an apalling error.
 
Last edited:
  • #3
Sir,
I am using a book prescribed for engineering entrance. I feel it may be useful for my GRE Physics exam. Though some of the answers may be wrong, I get so many questions from it. Thank you for your help Sir.
 

Related to Understanding Internal Energy: Path Dependence and Point Functions

1. What is meant by "change in the internal energy"?

Change in the internal energy refers to the difference in the total energy of a system before and after a process or reaction. It includes all forms of energy, such as thermal, chemical, and mechanical, that are present within the system.

2. How is the change in internal energy calculated?

The change in internal energy can be calculated by subtracting the initial energy of the system from its final energy. This can be done by considering the changes in heat, work, and any other forms of energy that may be involved in the process.

3. What factors can cause a change in the internal energy of a system?

Changes in the internal energy can be caused by a variety of factors, including the addition or removal of heat, work done on or by the system, and any chemical reactions that take place within the system. Changes in temperature, pressure, and volume can also contribute to a change in internal energy.

4. How does a change in internal energy affect the state of a system?

A change in internal energy can result in a change in the state of a system, such as a change in temperature, phase, or chemical composition. This is because the internal energy is closely related to the overall energy and stability of a system, and any changes in it can impact the system's equilibrium.

5. Can the change in internal energy be negative?

Yes, the change in internal energy can be negative. This indicates that the system has lost energy, either through heat or work, and its internal energy has decreased. Negative changes in internal energy are often associated with exothermic reactions or processes where work is done by the system.

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