Mu (letter)

From Wikinfo

Greek alphabet
Αα	Alpha	Ββ	Beta
Γγ	Gamma	Δδ	Delta
Εε	Epsilon	Ϝϝ	Wau
Ϛϛ	Stigma	Ζζ	Zeta
Ηη	Eta	Ͱͱ	Heta
Θθ	Theta	Ιι	Iota
Jϳ	Yot	Κκ	Kappa
Λλ	Lamda	Μμ	Mu
Νν	Nu	Ξξ	Xi
Οο	Omicron	Ππ	Pi
Ϻϻ	San	Ϸϸ	Sho
Ϙϙ	Koppa	Ρρ	Rho
Σσς	Sigma	Ττ	Tau
Υυ	Upsilon	Φφ	Phi
Χχ	Chi	Ψψ	Psi
Ωω	Omega	Ͳͳ	Sampi
Greek diacritics

Mu (uppercase Μ lowercase μ), is the letter of the Greek alphabet, used to represent the "[m]" sound in Greek. In the system of Greek numerals it has a value of 40. Letters that came from it include the Roman M and Cyrillic М.

The lower-case letter μ is used as the symbol for:

• The M??s function in mathematics.
• The SI prefix micro-, which represents one millionth, or 10^-6.
• Formerly, the micron, an old unit corresponding to the micrometer.
• The coefficient of friction, ie. the ratio of the limiting frictional force between two surfaces against the normal contact force.
• The elementary particle called muon in particle physics.
• Reduced mass in the two-body problem in physics.
• Rarely, to distinguish between one item represented by m and another (but m might be an easier option).
• The permeability in physics and electrical engineering.

References

• Adapted from the Wikipedia article, "Mu_(letter)" http://en.wikipedia.org/wiki/Mu_(letter), used under the GNU Free Documentation License