Questions tagged [mean-free-path]
The average length that a molecule will travel in a fluid before colliding with another molecule.
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Ion charge exchange mean free path
I am using the following equation to calculate the mean free path between a deuteron ion and background gas:
$$\lambda_{d-gas} = \frac{kT_{gas}}{p_{gas} \, \sigma_{10}}$$
Where $\sigma_{10}$ is the ...
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Viscosity and mean free path
I have troubles understanding how to derive the formula for viscosity in terms of the mean free path
$$\eta\sim \rho \lambda \bar v$$
where $\bar v$ is the average molecular velocity of the gas, $\...
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speed distribution and mean free path of gases at pressure
I know that at 18,000 ft. above mean sea level, the atm. pressure ~half of what it is at seal level (760 Torr). The temperature also decreases by 70C.
a. How would this change the speed distribution ...
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Mean free path in 2d? [duplicate]
Let us say we have a collection of $n$ stationary balls per square
meter each of diameter $d$ and we roll an identical ball between them.
Then what is the free mean path of this ball?
My ...
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Derivation of relativistic mean free path
I am working through a short derivation found in Abramowicz 1991 regarding the mean free path of a photon.
We have a fluid moving in a particular direction with velocity $v$ and in an inertial rest ...
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How photons get distributed in a system?
Let's say I'm in a room, and there are plenty of things in my room like carpet,mirrors,glass and other stuff.And I see there are shadow regions and fully bright regions, and I want to know how photons ...
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Mean free path in spherical coordinate
I am thinking about a distribution with spatially inhomogeneous cross section in spherical coordinate.
Starting with 1-dimensional case, a change of the flux passing through a slab with length $dx$ is ...
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Does it make sense to define the mean free path in quantum mechanics?
The mean free path defined in classical molecule dynamics has a strong classical flavor. Is it sensible to generalize the idea to quantum mechanics?
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Copper mean free path dependence on temperature
I'm doing simulations of copper, where the temperature can reach up to ~1300 K.
Some calculations depend on the mean free path (MFP) of copper. The only value I've found for it is 39nm and it's ...
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RMS Free Path vs Mean Free Path
I am trying to determine the mathematical difference between mean free path and root-mean-square free path. For an ideal gas, the relaxation time is $$\tau=\frac{1}{\sqrt2 \pi nd^2 \bar v}$$ and the ...
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Molecular mean free path probability
Let's let $p(\xi)$ be the probability a molecule travels at least $\xi$ between collisions, lets say $\xi=0.01$. When I think of this statement, I think it it is the probability the molecule is able ...
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Energy of particle in electric field
I'm taking a physics class and the professor teaches us really basic things in lecture and then gives homework way beyond what he taught in lecture. Obviously I need to find some resource other than ...
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Do particles in the solar core travel at the same speed as they would in vacuum?
I just read the Wikipedia article on the Sun. The section on Solar Core states
It has a density of up to 150 g/cm3[47][48] (about 150 times the density of water)
Do the particles (atomic, and sub-...
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The number of mean free paths which a particle traverses is independent of the material traversed
This is a manual from a Monte Carlo physics manual:
Computing the occurrence of a process
Can anyone tell me why the number of mean free paths of a particle is independent of the material which it ...
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Formula for mean free path in two dimensions
I'm running some simulations of particle collisions in two dimensions with discretised time and space. In essence, particles only collide if they occupy the same location (cell) at the same time step. ...
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