mean free path

noun

: the average distance traversed between collisions by particles (such as molecules of a gas or free electrons in metal) in a system of agitated particles

Examples of mean free path in a Sentence

Recent Examples on the Web
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For example, the mean free path of electrons in air under normal atmospheric pressure is about 200 nanometers, which on the scale of today’s transistors is pretty large. Jin-Woo Han, IEEE Spectrum, 23 June 2014 Water molecules are floating all around in the air, and their mean free path is around 100 nm. Andrew Paul, Popular Science, 24 May 2023

Word History

First Known Use

1879, in the meaning defined above

Time Traveler
The first known use of mean free path was in 1879

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Cite this Entry

“Mean free path.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mean%20free%20path. Accessed 27 Feb. 2025.

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