Question

What is the average value of time since last collision in Drude model?

Answer 1

Hello. ☺


According to me it states that the average time between collisions also to be equal to the average number of collisions per second.


Divide it by desired value and you will get average .

Answer 2

I have been following Feynman lectures on Physics.

Here he derives the average value of time till next collision over all molecules. He finds it to be equal to the average time between collisions τ. This concept is pretty clear.

Then he goes on to derive the drift velocity of molecules ( and in my case of interest,electrons) . Here he states that the average time between collisions also to be equal to the average number of collisions per second. My doubt lies here. I'm not able to mathematically prove how the average value of time since last collision to be equal to the average time between collisions. I checked up some online resources too, none of them explain this properly.