# Homework Help: Finding the mean free path using the given values?

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1. Oct 18, 2016

### joemmonster

1. The problem statement, all variables and given/known data

The concentration of electrons per unit volume is given (atoms/m^3), temperature is also given in Kelvins (100 K). Other values were also given such as valence but I'm pretty sure that they are irrelevant.
2. Relevant equations
λ = 1/ pi * d^2 * n
λ=kT/4∗π∗√2∗r^2*p
3. The attempt at a solution
n is given but I can't find other relevant values to be inserted in the equation since d is missing and the problem didn't provide it. On the second equation, pressure is missing but I don't know if I can assume that the pressure is 1 atm.

2. Oct 18, 2016

### haruspex

I assume we are dealing with some random distribution in space of identical bodies, and you want the mean distance one could travel in a straight line without striking another. What parameters do you think will matter?

3. Oct 18, 2016

### joemmonster

Ok, I just found out that conductivity is also given which I can finally derive mean free path by using mobility and relaxation time.