# Thermal conductivity of metal using kinetic theory of gases model

The first image gives the context about what i am gonna ask. Now in the second image i can understand upto the point where the book talks about kinectic theory in the second paragraph , after i am totally blank as to how it makes further calculations of energy and it also seems to deviate from the fact that heat energy is lost when it flows from A to B . It says energy of electrons at A is E and at B is E - ∆E . In this case i am unclear as to what it means by "energy transported" , i thought the energy transported to B from A was E - ∆E , since A has electrons with energy E and after loss of ∆E , remaining energy would be present with electrons at B . And then it gives another expression for energy transported from B to A , which makes no sense because at first it said heat was flowing from A to B . And then it says "net energy transported" from A to B , which again puts me into confusion as i am not able to differentiate between what the book said was "energy transported from A to B" and then "net energy transported" . Can anybody explain what is going on here? If i follow what is being done here ,it looks like i can just double the value of any energy flowing through two different points

All right, let’s we have a rod in which energy varies from point to point in the rod continuously. So, let’s assume that at point A the energy is $$E$$ and just after the point A (please I don’t want to clarify what “just after” really means) there is a point B such that the energy difference between these two points is $$\Delta E$$.

So, any particle at A have more energy than at B by the amount $$\Delta E$$. When the particle move from A to B it will lose $$\Delta E$$ amount of energy and this will try to establish the equilibrium of energy all along the rod.

Particles will not flow spontaneously from B to A.

Hope it helps!

• But what about the calculations they have made in the book , are they correct ? Feb 10, 2020 at 9:25
• As far as only those two pages are concerned it’s very hard to say that “electrons will from B to A” otherwise all calculations are correct. What are your problems?
– user240696
Feb 10, 2020 at 9:57
• I explained my problems in the question itself Feb 10, 2020 at 12:15
• @Maxwell’sGhost Then I’m sorry I cannot answer you.
– user240696
Feb 10, 2020 at 12:33
• Okay , but may i know why ? Feb 10, 2020 at 12:34