Questions tagged [mean-free-path]
The average length that a molecule will travel in a fluid before colliding with another molecule.
61
questions
0
votes
0
answers
41
views
Mean free path equation for plasma
Does the mean free path equation
$$\lambda=\frac{1}{\sqrt{2}\pi d^2 n_v}$$
work for collisions in plasma or just for gas?
- 33
0
votes
0
answers
13
views
Predicting electrical mean free path in nanostructures?
How does one roughly predict the
mean free path for
electrical conduction
in a nanostructure at different temperatures and under different electrical conditions such as different voltages and ...
0
votes
0
answers
52
views
Standard deviation for a free path distribution
I would like to be able to describe a particles path before collisions with greater precision. We can calculate the "mean" free path of a particle before colliding moving particles, but I ...
0
votes
1
answer
55
views
How is number of collisions per unit distance related to mean free path?
Recently I have been studying Kinetic Theory Of Gases, with one of the topics as collision frequency. I know that collision frequency is inverse of relaxation time which is also the measure of number ...
1
vote
0
answers
87
views
Determining the single particle energies in a neutrino opacity calculation
I'm attempting to recreate some plots from this paper on neutrino opacity calculations for interacting matter at supra-nuclear densities. Namely, I'm trying to write a Python script to perform the ...
- 799
0
votes
1
answer
39
views
Why does computing mean free path from an air molecule's reference frame seem to greatly overestimate path length?
I was interested in seeing if I could derive the mean free path of an "air molecule" by considering the reference frame of an individual molecule as other particles moved around it randomly. ...
- 1
4
votes
1
answer
169
views
Number of fog droplets in the air
I have an issue with the official solution to this problem from BelPhO:
Visibility on the road is 100 m. Assuming that the diameter of a fog
droplet is 1 micron, estimate the concentration of fog ...
- 439
0
votes
1
answer
187
views
Mean free path of molecules
So in the book concepts in thermal physics(by Stephan and Katherine Blundell) the expression of mean scattering time is derived as shown(please refer the book for more). If we replace vdt in the ...
- 353
0
votes
0
answers
33
views
Why is the sphere of influence of the molecule in mean free path a cylinder?
In my book for deriving mean free path a cylinder is taken to act as a sphere of influence of molecules with which it could bump into other molecules and its radius = diameter of the molecule we are ...
- 648
2
votes
1
answer
181
views
How does $\frac{\langle v\rangle}{\langle v_r\rangle}=\frac{1}{\sqrt2}$ imply the formula for the mean free path?
In this question, it was asked how the formula $$l=\frac{1}{\sqrt 2n\sigma }$$ can be rigorously derived for a Maxwell-Boltzmann gas.
Here $l$ is the mean free path length in a gas, $n$ is the gas ...
- 1,440
0
votes
0
answers
172
views
Free Path Probability Distribution for an Ideal Gas
Suppose we have a gas with collisions. The mean free path, $l$, is the average distance a particle travels before colliding with another particle. This is the average, but what is the probability ...
- 2,599
1
vote
0
answers
42
views
Question regarding correction factor in Mean free path
1)The expression for $Mean$ $Free$ $Path$ (ie) ,
$$λ=\dfrac{1}{πd²\dfrac{n}{V}}$$ is derived under the assumption that the particles except the one( let's consider it as particle $A$) you're ...
- 367
0
votes
1
answer
31
views
Collisional cross-section from attenuation factor
I am trying to find the mean free path of silver atoms travelling through air (I am given the temperature, pressure and that they are attenuated by a factor $2.72$ in a distance of $10^{-2}$m).
I know ...
- 75
2
votes
1
answer
133
views
Mean free path regarding billiards
Is there a generalization of the mean free path for macro-objects such as the distance the white billiard ball could travel before hitting an other billiard ball?
- 31
1
vote
0
answers
115
views
Ratio of mean free paths between two equal volumes at different temperature, separated by a partition with pinhole
Question:
A container is divided into two equal parts I and II by a partition with a small hole of diameter $d$. The two partitions are filled with same ideal gas, but held at temperatures $T_I$= ...
- 1,012