# Formula Symbols - E

Written by Jerry Ratzlaff on . Posted in Nomenclature & Symbols for Engineering, Mathematics, and Science

## Formula Symbols

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## E

SymbolGreek SymbolDefinitionUSMetricValue
earth age constant constant $$1.4327\;x\;10^{17}\;s$$
earth axial tilt constant constant $$0.407\;638\;19\;rad$$
earth average lunar month constant constant $$2.551\;4430\;x\;10^6\;s$$
earth core radius constant constant $$3.485\;x\;10^6\;m$$
earth dry land surface area constant constant $$1.489\;40\;x\;10^{14}\;m^2$$
earth equatorial surface gravity constant constant $$9.780\;327\;m\;s^{-2}$$
earth equatorial radius constant constant $$6.3781\;x\;10^6\;m$$
earth equatorial rotation speed constant constant $$465.1\;m\;s^{-1}$$
earth escape velocity constant constant $$1.1186\;x\;10^4\;m\;s^{-1}$$
earth mass constant constant $$5.9736\;x\;10^{24}\;kg$$
$$g$$   earth mean density constant  constant  $$5.515\;x\;10^3\;kg\;m^{-3}$$
earth mean surface pressure constant constant $$1.103\;25\;10^5\;kg\;m^{-1}\;s^{-2}$$
earth mean radius constant constant $$6.3710\;x\;10^6\;m$$
earth mean surface temperature constant constant $$287.2\;K$$
earth molar mass constant constant constant $$0.001\;kg\;mol^{-1}$$
earth polar radius constant constant $$6.3568\;x\;10^6\;m$$
earth surface area constant constant $$5.100\;720\;x\;10^{14}\;m^2$$
earth volume constant constant $$1.083\;21\;x\;10^{21}\;m^3$$
$$e$$ - eccentricity in mm  -
$$Ec$$ - Eckert number dimensionless dimensionless  -
$$I$$ - effective line current $$A$$ $$A$$  -
$$V$$ - effective line voltage $$V$$ $$V$$  -
$$m*_n$$, $$\;m*_p$$ - effective mass - -  -
$$E$$, $$\;\xi$$ xi effectiveness - -  -
$$\eta$$ eta efficiency % %  -
$$\Theta_e$$ Theta Einstein temperature - -  -
$$Ek$$ - Ekman number dimensionless dimensionless  -
$$E$$ - elastic - -  -
$$\lambda$$ lambda elastic modulus $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$  -
$$\lambda_c$$, $$\;E_c$$ lambda elastic modulus of concrete $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$ -
$$PE$$, $$\;E_p$$ - elastic potential energy $$ft-lbf$$ $$J$$  -
$$S$$ - elastic section modulus $$in^2$$ $$mm^2$$  -
$$E$$ - elasticity $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$  -
$$El$$ - elasticity number dimensionless dimensionless  -
$$q$$ - electric charge $$Ah$$ $$C$$  -
$$F$$ - electric capacitance $$C \;/\; V$$ $$C \;/\; V$$  -
$$S$$ - electric conductance $$A \;/\; V$$ $$A \;/\; V$$  -
$$\rho_{ik}$$ rho electric conductivity tensor - -  -
$$\varepsilon_0$$ varepsilon electric constant constant constant $$8.8542\;x\;10^{-12}\;s^2\;/\;kg\;m$$
$$I$$ - electric current - -  -
$$J$$, $$\;j$$ - electric current density - -  -
$$p$$ - electric dipole moment - -  -
$$D$$ - electric displacement - -  -
$$E$$ - electric field - -  -
$$\psi$$ psi electric flux - -  -
$$V$$, $$\;\phi$$ phi electric potential $$W \;/\; A$$ $$W \;/\; A$$  -
$$U_e$$ - electric potential energy $$ft-lbf$$ $$J$$  -
$$\Omega$$ Omega electric resistance $$V \;/\; A$$ $$V \;/\; A$$  -
$$X_c$$ - electric susceptibility - -  -
$$\sigma$$ sigma electrical conductivity - -  -
$$R_e$$ - electrical resistance $$\Omega$$ $$\Omega$$  -
$$\rho$$ rho electrical resistivity $$\Omega^{-in}$$ $$\Omega^{-cm}$$  -
$$e$$ - electron - -  -
$$E_{ea}$$ - electron affinity - -  -
$$\frac {m_c}{m_{\alpha}}$$   electron-$$\alpha$$  particle mass ratio - -  -
electron change / mas ratio constant constant $$-1.758\;820\;088\;x\;10^{11}\;kg^{-1}\;s\;A$$
$$w_{ce}$$ - electron cyclotron circular frequency - -  -
$$\frac {m_e}{m_d}$$ - electron-deuteron mass ratio - -  -
$$D_e$$ - electron diffusion coefficient - -  -
$$a_{ge}$$ - electron gravitational coupling constant dimensionless constant dimensionless constant $$2.40\;x\;10^{-43}$$
$$E_e$$ - electron rest energy constant constant $$8.1871\;x\;10^{-14}\;kg\;m^2\;/\;s^2$$
$$g_e$$ - electron g-factor dimensionless constant dimensionless constant $$-2.002\;319\;304\;362\;56$$
$$m_e$$ - electron rest mass constant constant $$9.109\;383\;701\;x\;10^{-31}\;kg$$
$$M \left( e \right)$$, $$\;M_e$$ - electron molar mass - -  -
$$\frac {m_c}{m_{\mu}}$$ mu electron-muon mass ratio - -  -
$$n_c$$ - electron number density - -  -
$$g_\lambda$$ lambda electron orbital g-factor dimensionless constant dimensionless constant $$0.993643364$$
$$O_e$$ - electron outer shell multiplier dimensionless constant dimensionless constant $$2.138743820$$
$$K_e$$ - electron partical wave center point dimensionless constant dimensionless constant $$10$$
$$w_{pe}$$ - electron plasma circular frequency - -  -
$$\frac {m_c}{m_p}$$ - electron-proton mass ratio dimensionless constant dimensionless constant $$5.446\;170\;2178\;x\;10^{-4}$$
$$r_e$$ - electron radius constant constant $$2.8179\;x\;10^{-15}\;m$$
$$\frac {-e}{m_e}$$ - electron specific charge - -  -
$$g_a$$ - electron spin g-factor dimensionless constant dimensionless constant $$0.976448541$$
$$T_e$$ - electron temperature - -  -
$$e$$ - electronic charge - -  -
$$u \;or\; w$$ - electromagnetic energy density - -  -
$$E$$, $$\;\varepsilon$$ varepsilon electromotive force (EMF) - -  -
$$F_e$$ - electrostatic force - -  -
$$dl$$, $$\;ds$$ - element of path - -  -
$$e$$, $$\;e_e$$ - elementary change constant constant $$1.602\;176\;634\;x\;10^{-19}\;C$$
$$y$$ - elevation $$ft$$ $$m$$  -
$$y_i$$ - elevation at inlet $$ft$$ $$m$$  -
$$y_o$$  - elevation at outlet $$ft$$ $$m$$  -
$$\Delta y$$ Delta elevation differential $$ft$$ $$m$$  -
$$E$$ - emission rate $$lb \;/\; hr$$ $$kg \;/\; hr$$ -
$$\epsilon$$ epsilon emissivity - -  -
$$E$$ - emissive power $$Btu \;/\; hr-ft^2$$ $$W \;/\; m^2$$  -
$$\gamma$$ gamma empirical constant $$1\;/\; F$$ $$1\;/\;C$$  -
$$\epsilon$$ epsilon empirical loss coefficient dimensionless dimensionless  -
$$r$$ - empirical rate - -  -
$$E$$, $$\;W$$ - energy $$ft-lbf$$ $$J$$  -
$$E$$, $$\;W$$ - energy $$Btu$$ $$kJ$$  -
$$E$$, $$\;W$$ - energy $$HP-hr$$ $$MJ$$  -
$$\Delta E$$ - energy differential $$ft-lbf$$ $$J$$  -
$$EER$$ - energy efficiency ratio $$Btu \;/\; W-hr$$ -  -
$$\epsilon$$ epsilon energy of particle - -  -
$$E_g$$ - energy gap - -  -
$$EHP$$, $$\;HP_e$$ - engine horsepower $$hp$$ - -
$$RPM$$ - engine speed rpm $$rad \;/\; s$$  -
$$H$$ - enthalpy $$ft-lbf$$ $$J$$  -
$$\large{ \partial H }$$ partial enthalpy rate of change - - -
$$S$$ - entropy $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$  -
$$\Delta S$$ Delta entropy differential $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$  -
$$\phi$$ phi entropy function $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$  -
$$Eo$$ - Eotvos number dimensionless dimensionless  -
$$K$$ - equilibrium constant - -  -
$$EW$$ - equivalent weight $$lbm\;/\;lbmol$$ $$kg\;/\;kmol$$  -
$$n$$, $$\;n_n$$, $$\;n^{12}$$ - electron number density - -  -
$$\gamma$$ gamma empirical constant $$1 \;/\; F$$ $$1 \;/\; C$$
-
$$r$$ - empirical rate constant $$1 \;/\; hr$$ $$1 \;/\; s$$  -
$$Er$$ - Ericksen number dimensionless dimensionless  -
$$v_e$$ - escape velocity $$ft\;/\;sec$$ $$m\;/\;s$$  -
$$A$$ - estimated annual soil loss $$ft^3$$ $$m^3$$ -
$$A_e$$, $$\;P_e$$ - Ettinghausen coefficient - -  -
$$Eu$$ - Euler number dimensionless constant dimensionless constant  $$2.718\;281\;828\;459...$$
$$\Delta h_f$$ Delta evaporation enthalpy change - -  -
$$\Theta_r$$ Theta Excess temperature coefficient dimensionless dimensionless  -
$$J$$ - exchange integral  - -  -
$$Y$$ - expansion coefficient - - -
$$Y$$ - expansion factor dimensionless dimensionless  -
$$e$$ - exponential constant - -  -
Symbol Greek Symbol Definition US Metric Value

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