Finding the mean free path using the given values?

In summary, the problem provides the concentration of electrons per unit volume and temperature in Kelvins. Other values such as valence are given but deemed irrelevant. The equations provided are λ = 1/ pi * d^2 * n and λ=kT/4∗π∗√2∗r^2*p, with n being the only relevant value given. However, the missing values of d and pressure make it difficult to solve the equations. The concept of mean free path can be applied by using the given value of conductivity and deriving it through mobility and relaxation time.
  • #1
joemmonster
10
0

Homework Statement



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.

Homework Equations


λ = 1/ pi * d^2 * n
λ=kT/4∗π∗√2∗r^2*p

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.
 
Physics news on Phys.org
  • #2
joemmonster said:

Homework Statement



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.

Homework Equations


λ = 1/ pi * d^2 * n
λ=kT/4∗π∗√2∗r^2*p

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

Related to Finding the mean free path using the given values?

1. What is the mean free path?

The mean free path is the average distance that a particle can travel between collisions with other particles. It is a measure of how far a particle can move freely before it interacts with another particle.

2. How is the mean free path calculated?

The mean free path is calculated by dividing the average distance a particle travels by the total number of collisions it experiences. This can be expressed mathematically as λ = 1/(Nσ), where λ is the mean free path, N is the number density of particles, and σ is the collision cross section.

3. What are the units for mean free path?

The units for mean free path depend on the system being studied and the units used for distance and number density. In general, mean free path is expressed in units of length, such as meters or micrometers.

4. What factors can affect the mean free path?

The mean free path can be affected by various factors, including the density of particles, the size and shape of particles, and the temperature and pressure of the system. In general, as the number density of particles increases, the mean free path decreases.

5. How is the mean free path used in scientific research?

The mean free path is an important concept in various fields of science, including physics, chemistry, and engineering. It is used to understand the behavior of particles in gases, liquids, and solids, and to calculate properties such as thermal conductivity and diffusion coefficients. It is also used in the design and analysis of various processes and technologies, such as gas sensors and semiconductor devices.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Biology and Chemistry Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
741
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
867
Back
Top