# What is Termodynamics: Definition and 16 Discussions

Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, radiation, and physical properties of matter. The behavior of these quantities is governed by the four laws of thermodynamics which convey a quantitative description using measurable macroscopic physical quantities, but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology.
Historically, thermodynamics developed out of a desire to increase the efficiency of early steam engines, particularly through the work of French physicist Nicolas Léonard Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars. Scots-Irish physicist Lord Kelvin was the first to formulate a concise definition of thermodynamics in 1854 which stated, "Thermo-dynamics is the subject of the relation of heat to forces acting between contiguous parts of bodies, and the relation of heat to electrical agency."
The initial application of thermodynamics to mechanical heat engines was quickly extended to the study of chemical compounds and chemical reactions. Chemical thermodynamics studies the nature of the role of entropy in the process of chemical reactions and has provided the bulk of expansion and knowledge of the field. Other formulations of thermodynamics emerged. Statistical thermodynamics, or statistical mechanics, concerns itself with statistical predictions of the collective motion of particles from their microscopic behavior. In 1909, Constantin Carathéodory presented a purely mathematical approach in an axiomatic formulation, a description often referred to as geometrical thermodynamics.

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1. ### B What is meant by "upper limit of work done on Earth"?

I think that the work is meant to be work done for instance in power stations. Or is it similar to work I do on a body when I lift it for example? But how can we then do that work on our Earth? I just need to understand the task, otherwise I want to solve it myself. The problem involves...
2. ### Find the molar specific heat for each gas.

Homework Statement A mixture of two ideal gases, the first one atomic and the second two atomic are put in normal conditions in a calorimeter with volume 1 liter hermetically closed. After it is given 10J thermal energy the mixture temperature is grown 14.2 K. Find the molar specific heat for...
3. ### Find the time needed to warm the water to a temperature

Homework Statement An electrical resistence has a power of 1 kW. It is put inside a container that has 10 liters water. The water is in temperature 20C with pressure 1 atm. Find the time to warm the water to the temperature 120C Homework Equations A=P*t The Attempt at a Solution I thought to...
4. ### Find the change of internal energy of the air.

Homework Statement A car rubber has the volume 50 liters when it is bloated in a pressur 1.8 atm and in a temperature 293 K. After some hours of journey as an effect of friction the pressure will become 2atm. Find the change of internal energy of the air inside the rubber (U) Homework...
5. ### Find the mass of ice that melts during the hit.

Homework Statement The sphere of lead with mass 2kg and velocity 20m/S hits a block of ice and is stuck in it. Find the mass of ice that melts during the hit. The initial temperature of the sphere is 293 K and c=128J/kg*grade. Homework Equations m1v1=m2v2 The Attempt at a Solution I thought...
6. ### Find the average velocity of the molecules of neon before an

Homework Statement A container has neon gas in the temperature 273 K. We heat the container to the temperature 373 k, keeping the volume constant. Find the average velocity of the molecules of neon before and after the heat. Homework Equations U=3/2vRT The Attempt at a Solution I thought to...
7. ### Find the growth of temperature of the gas

Homework Statement A mass of 3 mole gas is heated in a constant pressure of 1.5 atm, expanding from 40 litre to 60 litre. Find the temperature growth. Homework Equations V1/V2=T1/T2. The Attempt at a Solution I thought to write V1/V2=T1/T2. But I don't know T1. The answer is 121 K in my book.
8. ### Find the pressure of the elements.

Homework Statement A compound of ether (0.287 g) and chloroform (0.568 g) evaporates in the temperature 373 K in an empty container with volume 0.0001m3. Find the pressure of each element. I don't know which formula of ether should I use since there are many. However even if I knew the n of...
9. ### Need some info about light heat amplified by lens

It is known that a magnifing glass can start a fire, but I don't fully understand the phenomenon and I have the next questions: - Does the effect depend on the shape and the material of the lens you use? - Where can I find some details about heat produced by light or particulary on this...
10. ### Termodynamics: saturation pressure vs total air pressure

Hi! I have a question. The experiment goes like this. i hermetically close air and chloroform at standard pressure. now i want to calculate the end pressure of gas mixture after chloroform vapor gets saturated. is it as simple as adding up the chloroform saturated pressure to the starting air...
11. ### Solving Thermodynamics Doubt - João

I was solving the question below : "A cylinder have a piston whose mass is insignificant and moves without friction. One mole of an ideal gas is confined into the cylinder. If we expand isotermally the gass at temperature 298K, against a constant external pressure of 0.1 atm, the gas...
12. ### TERMODYNAMICS - gas leaking from container at T=const

Homework Statement Tank contain an ideal gas. Known is type of gas, temperature of gas T, volume of tank V=const, pressure of gas in tank p1, and the temperature of surrounding air T (same as temperature of gas in the tank). That is state 1. Tank has small valve that was not closed...
13. ### Cylinder,piston termodynamics problem

Homework Statement A closed vertical cylinder contains a mobile piston that splits it in two parts of volumes V1 and V2 with a ratio V1/V2=3. Both parts contain the same mass of an ideal gas at the same temperature T. Both chambers are heated to a temperature of 4T/3, find the ratio of the new...
14. ### Independent variables in termodynamics

Say I want to parametrize the plane. I can use cartesian (x,y) or polar (r,theta). But I cannot use x and r, because if I draw a circle and a vertical line, there are two points of intersection. I guess x and theta will do, because theta specifies a ray that will intersect any vertical line...
15. ### Termodynamics: heat supplied with loss of mass

Homework Statement Find the mass of liquid lead at fussion temperature needed to heat up 1kg of liquid water from 20ºC to 60ºC, considering P = 1 atm, and a loss of 100 mg of water due to local vaporization. My question is: what do I do with that loss of mass? Do I calculate Q for m =...
16. ### 2nd principle of termoDynamics

The second principle of termodynamics says: cooler object cannot give away heat spontaneously to warmer one. I wonder then how do cooler and wormer object appear in a closed system after they have equalized their heat.Or in other words: Is there a way back <=> Could this phenomenon be...