# Formula Symbols - M

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

## Formula Symbols

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## M

SymbolGreek SymbolDefinitionUSMetricValue
$$m_e$$ - electron (rest) $$lbm$$ $$kg$$ -
$$Ma$$ - Mach number dimensionless dimensionless  -
$$\Sigma$$ Sigma macroscopic cross section - -  -
$$M$$, $$\;m_i$$ - magnetic - -  -
$$\mu_o$$ mu magnetic constant constant constant $$1.2566\;x\;10^{-6}\;kg\;/\;m$$
$$B$$ - magnetic field - -  -
$$n_m$$, $$\;\nu_m$$ nu magnetic diffusivity - -  -
$$m$$, $$\;\mu$$ mu magnetic dipole moment - -  -
$$H$$, $$\;\vec{H}$$ - magnetic field - -  -
$$\phi_m$$ phi magnetic flux $$T$$ $$T$$  -
$$B$$ - magnetic flux density - $$T$$  -
$$\Phi_o$$ Phi magnetic flux quantum constant constant $$2.067\;833\;758\;x\;10^{-15}\;kg\;m^2\;s^{-2}\;A^{-1}$$
$$F_m$$ - magnetic force $$lbf$$ $$N \;/\; a-m$$  -
$$B$$, $$\;\vec{B}$$ - magnetic induction - -  -
$$\mu$$ mu magnetic moment of a particle - -  -
$$\mu$$ mu magnetic permeability - -  -
$$U_m$$ - magnetic potential difference - -  -
$$p_m$$ - magnetic pressure - -  -
$$\beta$$ beta magnetic pressure ratio - -  -
$$R_m$$ - Magnetic Reynolds number dimensionless dimensionless  -
$$X$$ - magnetic susceptibility - -  -
$$A$$ - magnetic vector potential - -  -
$$F_m$$ - magnetomotive force - -  -
$$M$$ - magnetization - -  -
$$M$$ - magnification - -  -
$$MF$$   magnification factor - -  -
$$h_{l-major}$$ - major head loss $$ft$$ $$m$$  -
$$v$$ - Manning equation $$ft\;/\;sec$$ $$m\;/\;s$$  -
$$n$$ - Manning friction coefficient - -  -
$$n$$ - Manning's roughness coefficient dimensionless dimensionless  -
$$Ma$$ - Marangoni number dimensionless dimensionless  -
$$MS$$, $$MOS$$ - margin of safety - - -
$$M$$ - Markstein number dimensionless dimensionless  -
$$m$$ - mass $$lbm$$ $$kg$$  -
$$M$$ - mass scale - - -
$$\mu_m$$ mu mass attenuation coefficient - -  -
$$\dot {m}_c$$ - mass condensation rate $$lbm\;/\;hr$$ $$kg\;/\;s$$  -
$$c$$ - mass consentration $$lbm$$ $$kg$$  -
$$\rho$$ rho mass density $$lb\;/\;ft^3$$ $$kg\;/\;m^3$$  -
$$D$$, $$\;D_m$$ - mass diffusivity $$ft^2/sec$$ $$m^2\;/\;s$$  -
$$\Delta$$ Delta mass excess - -  -
$$\dot {m}_f$$ - mass flow rate $$lbm\;/\;sec$$ $$kg\;/\;s$$  -
$$B$$, $$\;\Gamma$$ Gamma mass flow rate per unit area $$lbm\;/\;hr-ft^2$$ $$kg\;/\;s-m^2$$  -
$$w$$ - mass fraction - -  -
$$m$$, $$\;\dot {m}$$ - mass leak rate $$lbm\;/\;sec$$ $$kg\;/\;s$$  -
$$I$$ - mass moments of inertia $$lbm-ft^2$$ $$kg-m^2$$  -
$$A$$ - mass number - -  -
$$m_l$$ - mass of liquid $$lb$$ $$gr$$ -
$$\mu$$ mu mass of molecule - $$g/mol$$  -
$$m_s$$ - mass of solid $$lb$$ $$gr$$ -
$$K$$, $$\;k$$ - mass transfer coefficient $$ft/sec$$ $$m/s$$  -
$$\dot {m}_t$$ - mass transfer rate $$lbm\;/\;sec$$ $$kg\;/\;s$$  -
$$G$$ - mass velocity $$lbm\;/\;sec$$ $$kg\;/\;s$$  -
$$J$$ - Massieu function - -  -
$$D$$ - material density $$g \;/\; cm^3$$ $$kg \;/\; m^3$$  -
$$K_{cE}$$ - material factor for wood column design - -  -
$$S_f$$ - maximum allowable stress $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$ -
$$M$$ - maximum bending moment $$lbf-in$$ $$N-mm$$  -
$$\Delta_{max}$$ Delta maximum calculated beam deflection $$in$$ $$mm$$  -
$$P_{max}$$   maximum load - - -
$$M_u$$ - maximum moment from factored loads for LRFD beam design $$lbf-ft$$ $$N-m$$  -
$$\tau$$ tau maximum shear stress $$lb\;/\;in^2 \;or\; psi$$ $$kg \;/\; cm^2$$ -
$$S$$ - maximum soil moisture retention after runoff begins $$in$$ $$mm$$ -
$$H_{sp}$$ - maximum surge pressure head in a length of pipe $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$  -
$$P_{spf}$$ - maximum surge pressure for a fluid $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$  -
$$L_c$$ - maximum unbraced length of a steel beam in ASD design for max. allowed bending stress $$in \;or\; ft$$ $$mm \;or\;m$$  -
$$L_p$$ - maximum unbraced length of a steel beam in LRFD design for full plastic flexural strength $$in \;or\; ft$$ $$mm \;or\;m$$  -
$$L_r$$ - maximum unbraced length of a steel beam in LRFD design for inelastic strength $$in \;or\; ft$$ $$mm \;or\;m$$  -
$$L_u$$ - maximum unbraced length of a steel beam in ASD design for reduced allowed bending stress $$in \;or\; ft$$ $$mm \;or\; m$$  -
$$m$$, $$\;\mu$$ mu mean - -  -
$$h_m$$ - mean depth $$ft$$ $$m$$  -
$$v$$ - mean flow velocity $$ft\;/\;sec$$ $$m\;/\;s$$  -
$$l$$, $$\;\lambda$$ lambda mean free path $$ft$$ $$m$$  -
$$\tau$$, $$\;\tau_m$$ tau mean life - -  -
$$E_cm$$ - mean modulus of elasticity of concrete $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$ -
$$E_cm28$$ - mean modulus of elasticity of concrete at 28 days $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$ -
$$E_cmt$$ - mean modulus of elasticity of concrete at age t $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$ -
$$E_cmto$$ - mean modulus of elasticity of concrete when loading starts at age t_o $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$ -
$$v_m$$ - mean velocity $$ft\;/\;sec$$ $$m\;/\;s$$  -
$$h$$ - mean water depth $$ft$$ $$m$$  -
$$ME$$ - mechanical efficiency - -  -
$$ME$$ - mechanical energy $$ft-lbf$$ $$J$$  -
$$W$$ - mechanical work - $$J$$  -
$$\rho_m$$ rho media density $$lb\;/\;ft^3$$ $$kg\;/\;m^3$$  -
$$m$$ - midordinate $$in \;or\; ft$$ $$mm \;or\; m$$ -
$$Z_w$$ - metal removal rate $$ft^3\;/\;min$$ $$m_3\;/\;s$$  -
milky way galaxy diameter constant constant $$1.04\;x\;10^{21}\;m$$
milky way galaxy distance to center constant constant $$2.57\;x\;10^{20}\;m$$
milky way galaxy distance to closest neighbouring system constant constant $$3.970\;x\;10^{16}\;m$$
milky way galaxy mass constant constant $$2.50\;x\;10^{42}\;kg$$
milky way galaxy number of stars dimensionless constant dimensionless constant $$3.00\;x\;10^{11}$$
milky way galaxy oldest star known constant constant $$4.156\;x\;10^{17}\;s$$
milky way galaxy orbital speed rotation around center constant constant $$2.20\;x\;10^5\;m\;s^{-1}$$
milky way galaxy thickness constant constant $$1.00\;x\;10^{19}\;m$$
$$I_{min}$$ - minimum moment of inertia of $$I_x$$ and $$I_y$$ $$in \;or\; ft$$ $$mm \;or\; m$$  -
$$h_{l-minor}$$ - minor head loss $$ft$$ $$m$$  -
$$K$$ - minor loss coefficient - -  -
$$K$$ - mixing factor - -  -
$$\mu$$, $$\;\mu_n$$, $$\;\mu_p$$ mu mobility - -  -
$$b$$ - mobility ratio - -  -
$$C_m$$ - modification factor for combined stress in steel design - -  -
$$\lambda$$, $$\;E$$ lambda modulus of elasticity $$lb\;/\;ft^2 \;or\; psi$$ $$Pa$$  -
$$E$$ - modulus of elasticity earthquake load for LRFD design $$psi$$ $$kPa$$  -
$$U_r$$ - modulus of resilience $$lbf\;/\;in^2$$ $$MPa$$  -
$$G$$, $$\;\mu$$ mu modulus of rigidity $$Pa$$ $$Pa$$  -
$$G$$ - modulus of torsional $$Pa$$ $$Pa$$ -
$$U_t$$ - modulus of toughness $$lbf\;/\;in^2$$ $$MPa$$  -
$$n$$ - modular ratio - -  -
$$m$$ - module - $$mm$$  -
$$MC$$ - moisture content - -  -
$$m$$ - molality $$lb\;/\;mol$$ $$kg\;/\;mol$$  -
$$M$$ - molar concentration $$lbmol\;/\;ft^3$$ $$kmol\;/\;m^3$$  -
$$H$$ - molar enthalpy $$Btu\;/\;lbmol$$ $$kJ\;/\;kmol$$  -
$$S$$ - molar entropy $$Btu\;/\;lbmol-^\circ R$$ $$kJ\;/\;kmol-K$$  -
$$x$$ - molar fraction - -  -
$$M$$ - molar gas $$lb \;/\; mol$$ $$kg \;/\; mol$$  -
$$R$$ - molar gas constant constant constant $$8.314\;462\;618...\;J\;mol^{-1}\;K^{-1}$$
$$c_m$$ - molar heat $$lb\;/\;mol$$ $$kg\;/\;mol$$  -
$$U$$ - molar internal energy $$Btu\;/\;lbmol$$ $$kJ\;/\;kmol$$  -
$$M$$ - molar mass of gas - -  -
$$M$$ - molar mass $$lb\;/\;mol$$ $$kg\;/\;mol$$  -
$$M_u$$ - molar mass constant constant constant $$0.001\;kg\;mol^{-1}$$
$$M(^12 C)$$ - molar mass of carbon-12 constant constant $$11.999\;999\;9958\;x\;10^{-3}\;kg\;mol^{-1}$$
$$M_u$$ - molar mass constant constant constant $$0.999\;999\;999\;65\;x\;10^{-3}\;kg\;mol^{-1}$$
$$N_a h$$ - molar Planck constant constant constant $$3.990\;312\;712\;...\;x\;10^{-10}\;J\;Hz^{-1}\;mol^{-1}$$
$$r$$ - molar ratio of solution - -  -
$$C$$ - molar specific heat

$$Btu\;/\;lbmol-^\circ F$$

$$kJ\;/\;kmol-K$$  -
$$V$$ - molar specific volume $$ft^3\;/\;lbmol$$ $$m^3\;/\;kmol$$  -
$$V_m$$ - molar volume $$ft^3\;/\;mol$$ $$m^3\;/\;mol$$  -
$$V_m$$ - molar volume of ideal gas constant constant $$22.413\;968\;x\;10^{-3}\;m^3\;mol^{-1}$$
$$M$$ - molarity - $$mol\;/\;l$$  -
$$m$$ - molarity of solution - -  -
$$n$$ - mole - -  -
$$\chi$$ chi mole fraction $$mol$$ $$mol$$  -
$$MW$$ - molecular weight $$lbm\;/\;lbmol$$ $$kg\;/\;kmol$$  -
$$M$$ - moment $$lbf \;/\; sec$$ $$kg-m \;/\; s$$  -
$$M$$ - moment about the neuteal axis - - -
$$M$$ - moment of force $$lbf-ft$$ $$N-m$$  -
$$I$$, $$\;J$$ - moment of inertia $$lbm-ft2$$ $$kg-m^2$$  -
$$I_{cm}$$ - moment of inertia center of mass $$lbm-ft2$$ $$kg-m^2$$ -
$$I_c$$, $$\;\overline{I}$$ - moment of inertia about the centroid $$in^4$$ $$mm^4$$  -
$$I_x$$ - moment of inertia with respect to an x-axis $$in^4$$ $$mm^4$$  -
$$I_y$$ - moment of inertia with respect to an y-axis $$in^4$$ $$mm^4$$  -
$$p$$, $$\;\rho$$ rho momentum $$lbm-ft\;/\;sec$$ $$kg-m\;/\;s$$  -
$$M$$ - moment of mass $$lbf$$ $$kg-m$$ -
$$Mo$$ - Morton number dimensionless dimensionless  -
$$MHP$$, $$HP_m$$ - motor horsepower $$hp$$ - -
$$M$$ - mutual inductance - -  -
Symbol Greek Symbol Definition US Metric Value

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