# Thermal and stat. Physics question

• BurrowK
In summary, the conversation discusses the equations for a system with given variables A, N, V, and U. It also mentions the questions of what U, T, and P are for the system, as well as C_V and V. The final question is about the final temperature when two identical bodies with the same values of N and V and initial temperatures T_1 and T_2 are brought together. The equations dS=1/T dU+P/T dV-(mu)/T dN, U=TS-PV+\mu N, C_V=T(dS/dT)_{V,N}, and V=(dH/dP)_{S,N} may be helpful in solving these questions.
BurrowK
Given S=A*(N*V*U)^{1/3} where A is a constant.
a) What is U, T, and P for the system?
b) what are C_v and V?
c) 2 identical bodies consisting of a material obeying the equations found in A. N and V are the same for both and they are initially at temps T_1 and T_2. The two bodies are brought together, what is the final temp?

I know that dS=1/T dU+P/T dV-(mu)/T dN, but I'm not sure how this helps.

I'm unsure where to start for this, my prof forgot to lecture on the subject before giving us this question. ANy help is appreciated.

Last edited:
Hi BurrowK, welcome to PF. From your dS equation it looks like

$$\frac{1}{T}=\left(\frac{dS}{dU}\right)_{V,N}$$

which should help your figure out T (and P can be calculated similarly). It may also help that

$$U=TS-PV+\mu N$$

$$C_V=T\left(\frac{dS}{dT}\right)_{V,N}$$

$$V=\left(\frac{dH}{dP}\right)_{S,N}$$

where the enthalpy $H=U+PV$. Does this get you started?

## 1. What is thermal physics?

Thermal physics is a branch of physics that deals with the study of heat and its relationship to energy and temperature. It involves the behavior of matter at the molecular level and how it responds to changes in temperature.

## 2. What is statistical physics?

Statistical physics is a branch of physics that uses statistical methods to explain and predict the behavior of large groups of particles. It helps to understand the properties of matter and how they relate to the laws of thermodynamics.

## 3. What is the difference between thermal and statistical physics?

Thermal physics deals with the macroscopic behavior of matter and its relationship to heat and energy, while statistical physics focuses on the microscopic behavior of particles and their statistical properties.

## 4. What are the laws of thermodynamics?

The laws of thermodynamics are fundamental principles that govern the behavior of energy and heat in a system. These laws state that energy cannot be created or destroyed, and that the total entropy of an isolated system will always increase.

## 5. How is thermal and statistical physics applied in real-life situations?

Thermal and statistical physics have numerous applications in various fields, such as engineering, chemistry, and biology. They are used to design efficient energy systems, understand the behavior of materials, and predict the properties of complex systems, such as weather patterns and biological processes.

Replies
4
Views
1K
Replies
4
Views
896
Replies
1
Views
1K
Replies
1
Views
867
Replies
5
Views
1K
Replies
1
Views
3K
Replies
3
Views
5K
Replies
2
Views
6K