Rho - wikipedia Rho For other uses, see Rho ( disambiguation ). Greek alphabet Αα Alpha Νν Nu Ββ Beta Ξξ Xi Γγ Gamma Οο Omicron Δδ Delta Ππ Pi Εε Epsilon Ρρ Rho Ζζ Zeta Σσς Sigma Ηη Eta Ττ Tau Θθ Theta Υυ Upsilon Ιι Iota Φφ Phi Κκ Kappa Χχ Chi Λλ Lambda Ψψ Psi Μμ Mu Ωω Omega History Archaic local variants Diacritics Ligatures Numerals ϛ ( 6 ) ϟ ( 90 ) ϡ ( 900 ) Use in other languages Bactrian Coptic Albanian Related topics Use as scientific symbols Book Commons Rho ( / roʊ / ; uppercase Ρ, lowercase ρ or ρ ; Greek : ῥῶ ) is the 17th letter of the Greek alphabet. In the system of Greek numerals, it has a value of 100. It is derived from Phoenician letter res. Its uppercase form uses the same glyph, Ρ, as the distinct Latin letter P ; the two letters have different Unicode encodings. Contents 1 Uses 1.1 Greek 1.2 Other alphabets 1.3 Mathematics and science 1.4 Chi Rho 1.5 Rhodes Scholars 2 Character encodings 2.1 Greek Rho 2.2 Greek Rho symbols 2.3 Coptic Ro 2.4 Functional Symbol 2.5 Mathematical Rho 3 See also 4 References Uses The Greek alphabet on a black figure vessel, with an R - shaped rho. Greek Rho is classed as a liquid consonant ( together with lambda and sometimes the nasals mu and nu ), which has important implications for morphology. In both Ancient and Modern Greek, it represents a trilled or tapped r. In polytonic orthography, a rho at the beginning of a word is written with a rough breathing, equivalent to h ( ῥ rh, and a double rho within a word is written with a smooth breathing over the first rho and a rough breathing over the second ( ῤῥ rrh ). That apparently reflected an aspirated or voiceless pronunciation in Ancient Greek, which led to the various Greek - derived English words starting with rh or contain rrh. The name of the letter is written in Greek as ῥῶ ( polytonic ) or ρω / ρο ( monotonic ). Other alphabets Letters that arose from rho include Roman R and Cyrillic Er ( Р ). Mathematics and science The characters ρ and ρ are also conventionally used outside the Greek alphabetical context in science and mathematics. In the physical sciences to represent : Densities : mass density, air density or charge density ( ρ ) Resistivity ( ρ ) Rho meson ( ρ, ρ, ρ ) General quantum states Hammett Equation, ρ is used to represent the reaction constant, this is independent of the position and nature of the substituents of the benzene ring. In mathematics to represent : A length coordinate in polar, cylindrical, spherical, and toroidal coordinate systems, and toroidal and poloidal coordinates of the Earth 's magnetic field. The correlation coefficient of a population parameter The spectral radius of a matrix A ( displaystyle A ) denoted as ρ ( A ) ( displaystyle \rho ( A ) ) The plastic number The ' prime constant ' number The sensitivity to interest rates of a pricing function The expected return of a given policy ( π ( displaystyle pi ) ) in reinforcement learning, denoted ρ π ( displaystyle \rho ^ ( pi ) ) In economics to represent the discount rate of future pence cash flows In molecular biology to represent the Rho protein responsible for termination of RNA synthesis. In such occasions, it is often represented as ρ ( `` rho symbol '' U + 03F1 ), to avoid confusion with the Latin letter p In ecology to represent the population damping ratio where ρ = λ1 / λ2. In computer programming For LaTeX, the symbols are \rho ( ρ ( displaystyle \rho ) ), and \varrho ( ρ ( displaystyle \varrho ) ) ( note : Rho is not defined by default ) The lower - case rho `` ρ '' has a special meaning in the APL programming language In statistics to represent Spearman 's rank correlation coefficient, commonly known as Spearman 's rho In options theory to represent the rate of change of a portfolio with respect to interest rates Chi rho The letter rho overlaid with chi forms the Chi Rho symbol, used to represent Jesus Christ. Rhodes Scholars Former Rhodes Scholars are entitled to use the Greek letter rho as a designation of their status. When used, the symbol should precede the name. Character encodings Greek Rho Character Ρ ρ Ῥ ῥ ῤ Unicode name GREEK CAPITAL LETTER RHO GREEK SMALL LETTER RHO GREEK CAPITAL LETTER RHO WITH DASIA GREEK SMALL LETTER RHO WITH DASIA GREEK SMALL LETTER RHO WITH PSILI Encodings decimal hex decimal hex decimal hex decimal hex decimal hex Unicode 929 U + 03A1 961 U + 03C1 8172 U + 1FEC 8165 U + 1FE5 8164 U + 1FE4 UTF - 8 206 161 CE A1 207 129 CF 81 225 191 172 E1 BF AC 225 191 165 E1 BF A5 225 191 164 E1 BF A4 Numeric character reference & # 929 ; & # x3A1 ; & # 961 ; & # x3C1 ; & # 8172 ; & # x1FEC ; & # 8165 ; & # x1FE5 ; & # 8164 ; & # x1FE4 ; Named character reference &Rho ; &rho ; DOS Greek 144 90 168 A8 DOS Greek - 2 199 C7 235 EB Windows 1253 209 D1 241 F1 TeX \rho Greek Rho symbols Character ρ ϼ ᴩ ρ ☧ Unicode name GREEK RHO SYMBOL GREEK RHO WITH STROKE SYMBOL GREEK LETTER SMALL CAPITAL RHO GREEK SUBSCRIPT SMALL LETTER RHO CHI RHO Encodings decimal hex decimal hex decimal hex decimal hex decimal hex Unicode 1009 U + 03F1 1020 U + 03FC 7465 U + 1D29 7528 U + 1D68 9767 U + 2627 UTF - 8 207 177 CF B1 207 188 CF BC 225 180 169 E1 B4 A9 225 181 168 E1 B5 A8 226 152 167 E2 98 A7 Numeric character reference & # 1009 ; & # x3F1 ; & # 1020 ; & # x3FC ; & # 7465 ; & # x1D29 ; & # 7528 ; & # x1D68 ; & # 9767 ; & # x2627 ; TeX \varrho Coptic ro Character Ⲣ ⲣ ⳩ Unicode name COPTIC CAPITAL LETTER RO COPTIC SMALL LETTER RO COPTIC SYMBOL CHI RHO Encodings decimal hex decimal hex decimal hex Unicode 11426 U + 2CA2 11427 U + 2CA3 11497 U + 2CE9 UTF - 8 226 178 162 E2 B2 A2 226 178 163 E2 B2 A3 226 179 169 E2 B3 A9 Numeric character reference & # 11426 ; & # x2CA2 ; & # 11427 ; & # x2CA3 ; & # 11497 ; & # x2CE9 ; Functional Symbol Character ⍴ Unicode name APL FUNCTIONAL SYMBOL RHO Encodings decimal hex Unicode 9076 U + 2374 UTF - 8 226 141 180 E2 8D B4 Numeric character reference & # 9076 ; & # x2374 ; Mathematical Rho Character Ρ ρ ρ Ρ ρ Unicode name MATHEMATICAL BOLD CAPITAL RHO MATHEMATICAL BOLD SMALL RHO MATHEMATICAL BOLD RHO SYMBOL MATHEMATICAL ITALIC CAPITAL RHO MATHEMATICAL ITALIC SMALL RHO Encodings decimal hex decimal hex decimal hex decimal hex decimal hex Unicode 120504 U + 1D6B8 120530 U + 1D6D2 120544 U + 1D6E0 120562 U + 1D6F2 120588 U + 1D70C UTF - 8 240 157 154 184 F0 9D 9A B8 240 157 155 146 F0 9D 9B 92 240 157 155 160 F0 9D 9B A0 240 157 155 178 F0 9D 9B B2 240 157 156 140 F0 9D 9C 8C UTF - 16 55349 57016 D835 DEB8 55349 57042 D835 DED2 55349 57056 D835 DEE0 55349 57074 D835 DEF2 55349 57100 D835 DF0C Numeric character reference & # 120504 ; & # x1D6B8 ; & # 120530 ; & # x1D6D2 ; & # 120544 ; & # x1D6E0 ; & # 120562 ; & # x1D6F2 ; & # 120588 ; & # x1D70C ; Character ρ Ρ ρ ρ Ρ Unicode name MATHEMATICAL ITALIC RHO SYMBOL MATHEMATICAL BOLD ITALIC CAPITAL RHO MATHEMATICAL BOLD ITALIC SMALL RHO MATHEMATICAL BOLD ITALIC RHO SYMBOL MATHEMATICAL SANS - SERIF BOLD CAPITAL RHO Encodings decimal hex decimal hex decimal hex decimal hex decimal hex Unicode 120602 U + 1D71A 120620 U + 1D72C 120646 U + 1D746 120660 U + 1D754 120678 U + 1D766 UTF - 8 240 157 156 154 F0 9D 9C 9A 240 157 156 172 F0 9D 9C AC 240 157 157 134 F0 9D 9D 86 240 157 157 148 F0 9D 9D 94 240 157 157 166 F0 9D 9D A6 UTF - 16 55349 57114 D835 DF1A 55349 57132 D835 DF2C 55349 57158 D835 DF46 55349 57172 D835 DF54 55349 57190 D835 DF66 Numeric character reference & # 120602 ; & # x1D71A ; & # 120620 ; & # x1D72C ; & # 120646 ; & # x1D746 ; & # 120660 ; & # x1D754 ; & # 120678 ; & # x1D766 ; Character ρ ρ Ρ ρ ρ Unicode name MATHEMATICAL SANS - SERIF BOLD SMALL RHO MATHEMATICAL SANS - SERIF BOLD RHO SYMBOL MATHEMATICAL SANS - SERIF BOLD ITALIC CAPITAL RHO MATHEMATICAL SANS - SERIF BOLD ITALIC SMALL RHO MATHEMATICAL SANS - SERIF BOLD ITALIC RHO SYMBOL Encodings decimal hex decimal hex decimal hex decimal hex decimal hex Unicode 120704 U + 1D780 120718 U + 1D78E 120736 U + 1D7A0 120762 U + 1D7BA 120776 U + 1D7C8 UTF - 8 240 157 158 128 F0 9D 9E 80 240 157 158 142 F0 9D 9E 8E 240 157 158 160 F0 9D 9E A0 240 157 158 186 F0 9D 9E BA 240 157 159 136 F0 9D 9F 88 UTF - 16 55349 57216 D835 DF80 55349 57230 D835 DF8E 55349 57248 D835 DFA0 55349 57274 D835 DFBA 55349 57288 D835 DFC8 Numeric character reference & # 120704 ; & # x1D780 ; & # 120718 ; & # x1D78E ; & # 120736 ; & # x1D7A0 ; & # 120762 ; & # x1D7BA ; & # 120776 ; & # x1D7C8 ; These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style. See also Р, р - Er ( Cyrillic ) R, r - Latin P, p - Latin References Look up Ρ or ρ in Wiktionary, the free dictionary. Jump up ^ `` Oxford University Calendar : Notes on Style '' ( PDF ). Oxford University Gazette. 2011 - 03 - 03. Retrieved 2011 - 09 - 08. Jump up ^ Unicode Code Charts : Greek and Coptic ( Range : 0370 - 03FF ) Retrieved from `` https://en.wikipedia.org/w/index.php?title=Rho&oldid=811759108 '' Categories : Greek letters Hidden categories : Articles containing Greek - language text Articles containing Ancient Greek - language text Talk Contents About Wikipedia Afrikaans Alemannisch ܐܪܡܝܐ Bân - lâm - gú Беларуская Беларуская ( тарашкевіца ) ‎ Български Boarisch བོད ་ ཡིག Brezhoneg Català Čeština Cymraeg Dansk Davvisámegiella Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Français Gaeilge Gàidhlig Galego 한국어 Հայերեն Hrvatski Bahasa Indonesia Íslenska Italiano עברית ქართული Kiswahili Коми Kreyòl ayisyen Kurdî Лезги Latina Latviešu Lëtzebuergesch Lietuvių Magyar मराठी Bahasa Melayu Mìng - dĕ̤ng - ngṳ̄ Nāhuatl Nederlands 日本 語 Norsk Norsk nynorsk Occitan ਪੰਜਾਬੀ Plattdüütsch Polski Português Română Русский संस्कृतम् Scots Simple English Slovenčina Slovenščina کوردی Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska ไทย Türkçe Українська Vepsän kel ' Tiếng Việt Winaray 吴语 粵語 Zazaki 中文 Edit links This page was last edited on 23 November 2017, at 19 : 28. 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Question: what does the greek letter rho mean in physics
Answer: Densities: mass density, air density or charge density (ρ)