Formula Symbols - A
Nomenclature and Symbols Glossary
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Formula Symbols
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
A
| Symbol | Greek Symbol | Definition | English | Metric | SI | Value |
|---|---|---|---|---|---|---|
| \(V_d\) | - | Abbe number | dimensionless | - | ||
| \(T\) | absolute dry bulb temperature | - | \(K\) | \(K\) | - | |
| \(AH\) | - | absolute humidity | \(\large{\frac{lbm}{ft^3}}\) | \(\large{\frac{g}{m^3}}\) | \(g - m^{-3}\) | - |
| \(p_a\) | - | absolute pressure | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(\epsilon \) | epsilon | absolute roughness | \(in\) | \(mm\) | \(mm\) | - |
| \(T_a\) | - | absolute temperature | \(F\) | \(C\) | \(x+273.15\;K\) | - |
| \(R_t\) | - | absolute thermal resistance | - | - | - | - |
| \(\mu \) | mu | absolute viscosity | \(\large{\frac{lbf-sec}{ft^2}}\) | \(Pa-s\) | \(kg - m^{-1} - s^{-1}\) | - |
| \(\alpha\) | alpha | absorptance | - | - | - | - |
| \(\alpha\) | alpha | absorptivity | - | - | - | - |
| \(a\) | - | acceleration | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) | \(m - s^{-2}\) | - |
| \(a\) | - | acceleration from force | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) | \(m - s^{-2}\) | - |
| \(g\) | acceleration of free fall | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) | \(m - s^{-2}\) | - | |
| \(g\) | - | acceleration of gravity | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) | \(m - s^{-2}\) | \(9.806\;65\) \(\large{\frac{m}{s^2}}\) |
| \(\omega\) | omega | acentric factor | dimensionless | - | ||
| \(acfm\) | - | ACFM | \(\large{\frac{ft^3}{min}}\) | \(\large{\frac{m^3}{min}}\) | \(m^3 - ^min{-1}\) | - |
| \(\gamma\) | gamma | activity coefficient | dimensionless | - | ||
| \(E_a\) | - | activation energy | \(lbf-ft\) | \(J\) | \(kg - m^2 - s^{-2}\) | - |
| \(ACFM\) | - | actual flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) | \(m^3 - s^{-1}\) | - |
| \(e\) | - | actual vapor pressure | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(l\) | - | acoustic path length between tranducer faces | \(ft\) | \(m\) | \(m\) | - |
| \(p\) | - | acoustic pressure | \(\large{\frac{lbf-sec}{ft^2}}\) | \(Pa\) | \(kg-m^{-1}-s^{-1}\) | - |
| \(t_d\) | - | accustic signal downstream travel time | \(sec\) | \(s\) | \(s\) | - |
| \(t_u\) | - | accustic signal downstream travel time | \(sec\) | \(s\) | \(s\) | - |
| - | - | adjusts for the volume occupied by the gas particles | \(in^3\) | \(mm^3\) | \(mm^3\) | - |
| \(N_a\) | - | aeration number | dimensionless | - | ||
| \(A\) | - | affinity | - | - | - | - |
| \(t\) | - | age of concrete | \(days\) | \(days\) | \(days\) | - |
| \(t_o\) | - | age of concrete at loading | \(days\) | \(days\) | \(days\) | - |
| \(t_c\) | age of concrete when drying starts at end of moist curing | \(days\) | \(days\) | \(days\) | - | |
| \(a\) | - | aggregate content of concrete | \(\large{\frac{lbm}{yd^3}}\) | \(\large{\frac{kg}{m^3}}\) | \(kg - m^{-3}\) | - |
| \(A\) | - | air | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(\alpha\) | alpha | air content expressed as percentage | dimensionless | - | ||
| \(ACR\) | - | air consumption rate | \(\large{\frac{ft^3}{min}}\) | \(\large{\frac{m^3}{min}}\) | \(m^3-min^{-1}\) | - |
| \(A\) | - | air content | dimensionless | - | ||
| \(CFM\), \(\;Q_a\) | - | air flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) | \(m^3 - s^{-1}\) | - |
| \(Q_a\) | - | air flow rate through piping | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) | \(m^3 - s^{-1}\) | - |
| \(AFR\) | - | air-fuel ratio | dimensionless | - | ||
| \(AHP\) | - | air horsepower | \(\large{\frac{lbf-ft}{sec}}\) | \(\large{\frac{J}{s}}\) | \(J - s^{-1}\) | - |
| \(T_i\) | - | air inlet temperature | \(F\) | \(C\) | \(x+273.15\;K\) | - |
| \( m_a\) | - | air mixture | \(lbm\) | \(kg\) | \(kg\) | - |
| \(T_o\) | - | air outlet temperature | \(F\) | \(C\) | \(x+273.15\;K\) | - |
| \(d\) | - | air pipe sizing | \(in\) | \(mm\) | \(mm\) | - |
| \(p\) | - | air pressure | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(p_l\) | - | air pressure loss through piping | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(F_a\) | - | air resistance | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(F_a\) | - | air resistance of drag | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(F_a\) | - | air resistance force | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(c_a\) | - | air specific heat | \(\large{\frac{Btu}{lbm-F}}\) | \(\large{\frac{kJ}{kg-K}}\) | \(kJ - kg^{-1} - K^{-1}\) | - |
| \(\gamma_a\) | gamma | air specific weight | \(\large{\frac{lbf}{ft^3}}\) | \(\large{\frac{N}{m^3}}\) | \(N - m^{-3}\) | - |
| \(v_a\) | - | air velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(v_a\) | - | air velocity through piping | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(s\) | - | AGMA stress number | - | - | - | - |
| \(Al\) | - | Alfven number | dimensionless | - | ||
| \(v_a\) | - | Alfven speed | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(A\) | - | algebric difference in grade | dimensionless | - | ||
| \(F_a\) | - | allowable axial stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(F_b\) | - | allowable bending stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(F_c\) | - | allowable compressive stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(P_a\) | - | allowable load | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(F_v\) | - | allowable shear stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(S\) | - | allowable stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(ASD\) | - | allowable stress design | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(S_a\) | - | allowable stress range | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(F_t\) | - | allowable tensile stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(A\) | - | allowance | - | - | - | - |
| \(m_a\) | - | alpha particle mass | \(lbm\) | \(kg\) | \(kg\) | \(6.644\;657\;230\;(82)\;x\;10^{-27}\) \(kg\) |
| \(AC\) | - | alternating current | \(I\) | \(\large{\frac{C}{s}}\) | \(C - s^{-1}\) | - |
| \(V_{mixture}\) | - | Amagat's law | \(ft^3\) | \(m^3\) | \(m^3\) | - |
| \(T_a\) | - | ambient temperature | \(F\) | \(C\) | \(x+273.15\;K\) | - |
| \(n\) | - | amount of substance | - | - | - | - |
| \(A\) | - | amp | \(I\) | \(\large{\frac{C}{s}}\) | \(C - s^{-1}\) | - |
| \(A\) | - | ampere | \(I\) | \(\large{\frac{C}{s}}\) | \(C - s^{-1}\) | - |
| \(A\) | - | amplitude | \(in\) | \(mm\) | \(mm\) | - |
| \(A_l\) | - | amplitude (longitudinal) | \(in\) | \(mm\) | \(mm\) | - |
| \(AR\) | - | amplitude ratio | - | - | - | - |
| \(\beta\) | beta | Andrade's beta | - | - | - | - |
| \(\theta\), \(\;\phi\) | theta, phi | angular deflection | \(deg\) | \(rad\) | \(rad\) | - |
| \(\omega\) | omega | angular frequency | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(A\), \(\;B\), \(\;C\) | - | Antoine constant | - | - | - | - |
| - | - | Antoine equation | \(\large{\frac{lbf}{in^2}}\) | \(\large{\frac{kg}{m-s^2}}\) | \(kg - m^{-1} - s^{-2}\) | - |
| \(A\), \(\;\theta\), \(\;deg\) | theta | angle | \(deg\) | \(rad\) | \(rad\) | - |
| \(\phi\) | phi | angle | \(deg\) | \(rad\) | \(rad\) | - |
| \(\theta\) | theta | angle between a perpendicular vector to the area and the magnertic field | \(deg\) | \(rad\) | \(rad\) | - |
| \(\theta\) | theta | angle between acoustic path and the pipe's longitudinal axis | \(deg\) | \(rad\) | \(rad\) | - |
| \(\Delta A\) | delta | angle differential | \(deg\) | \(rad\) | \(rad\) | - |
| \(Imp\) | - | angle impulse | \(lbf-ft-sec\) | \(N-m-s\) | \(N-m-s\) | - |
| \(\theta\) | theta | angular rotation | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(\gamma \) | gamma | angle of twist | \(deg\) | \(rad\) | \(rad\) | - |
| \(\alpha\) | alpha | angular acceleration | \(\large{\frac{deg}{sec^2}}\) | \(\large{\frac{rad}{s^2}}\) | \(rad - s^{-2}\) | - |
| \(\theta\) | theta | angular deflection | \(in\) | \(mm\) | \(mm\) | - |
| \(\theta \) | theta | angular displacement | \(deg\) | \(rad\) | \(rad\) | - |
| \(\omega\) | omega | angular frequency | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(H\) | - | angular impulse | \(\large{\frac{lbm-ft^2}{sec}}\) | \(\large{\frac{kg-m^2}{s}}\) | \(kg-m^2-s^{-1}\) | - |
| \(L\) | - | angular momentum | \(\large{\frac{lbm-ft^2}{sec}}\) | \(\large{\frac{kg-m^2}{s}}\) | \(kg-m^2-s^{-1}\) | - |
| \(L\) | - | angular momentum of an object with linear momentum | \(\large{\frac{lbm-ft^2}{sec}}\) | \(\large{\frac{kg-m^2}{s}}\) | \(kg-m^2-s^{-1}\) | - |
| - | - | angular Planck constant | \(\large{\frac{lbf-ft}{sec}}\) | \(J-s\) | \(kg-m^2-s^{-1}\) | \(1.054\;571\;726\;(47)\;x\;10^{-34}\) \(J-s\) |
| \(\theta\) | theta | angular position | \(deg\) | \(rad\) | \(rad\) | - |
| \(\omega_0\) | omega | angular resonant frequency | \(\large{\frac{1}{sec}}\) | \(\large{\frac{1}{s}}\) | \(1 - s^{-1}\) | - |
| \(\theta\) | theta | angular rotation | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(\omega\) | omega | angular speed | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(\omega\), \(\;v_a\) | omega | angular velocity | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(d \omega\), \(\;\Delta \omega \) | omega | angular velocity differential | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(\omega\) | omega | angular velovity of a rolling sphere | \(\large{\frac{deg}{sec}}\) | \(\large{\frac{rad}{s}}\) | \(rad - s^{-1}\) | - |
| \(k\) | - | angular wavenumber | \(\large{\frac{rad}{ft}}\) | \(\large{\frac{rad}{m}}\) | \(rad - m^{-1}\) | - |
| \(k\) | - | angular wave vector | - | - | - | - |
| \(API_{gravity}\) | API gravity | \(F\) | \(C\) | \(x+273.15\;K\) | - | |
| \(a\) | - | apothem | \(in\) or \(ft\) | \(mm\) or \(m\) | \(mm\) or \(m\) | - |
| \(P\) | - | applied concentrated load | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(w\) | - | applied distributed load | \(lbf\) | \(N\) | \(kg-m-s^{-2}\) | - |
| \( F_a\) | - | applied force | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(R\) | - | applied stress | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(Ar\) | - | Archimedes number | dimensionless | - | ||
| \(B\) | - | Archimede's principle | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(E\), \(\;V\) | - | arc voltage | \(V\) | \(V\) | \(kg - m^2 - s^{-3} - A^{-1}\) | - |
| \(\overset{\frown}{l}\), \(\; l_a\) | - | arc length | \(in\) or \(ft\) | \(mm\) or \(m\) | \(mm\) or \(m\) | - |
| \(A\), \(\;S\) | - | area | \(in^2\) or \(ft^2\) | \(mm^2\) or \(m^2\) | \(mm^2\) or \(m^2\) | - |
| \(A\), \(\;A_c\) | - | area cross-section | \(in^2\) or \(ft^2\) | \(mm^2\) or \(m^2\) | \(mm^2\) or \(m^2\) | - |
| \(A_{throat}\) | - | area cross the throat of a weld | \(in^2\) or \(ft^2\) | \(mm^2\) or \(m^2\) | \(mm^2\) or \(m^2\) | - |
| \(A_d\) | - | area differential | \(in^2\) or \(ft^2\) | \(mm^2\) or \(m^2\) | \(mm^2\) or \(m^2\) | - |
| \(f_a\) | - | area gradient | - | - | - | - |
| \(\Delta A\) | - | area thermal expansion | \(in^2\) | \(mm^2\) | \(mm^2\) | - |
| \(\alpha_a\) | alpha | area thermal expansion coefficient | \(\large{ \frac{in^2}{in^2\;F} }\) | \(\large{ \frac{mm^2}{mm^2-C} }\) | \(mm^2-mm^{-2}-C^{-1}\) | - |
| \(Ar\) | - | Arrhenius number | dimensionless | - | ||
| \(k\) | - | Arrhenius equation | - | \(\large{ \frac{mol}{L-s} }\) | \(mol- L^{-1}-s^{-1}\) | - |
| \(\rho\) | rho | atmosphere density | \(\large{\frac{lbm}{ft^3}}\) | \(\large{\frac{kg}{m^3}}\) | \(kg-m^{-3}\) | - |
| \(p_a\), \(\;p_{atm}\) | - | atmospheric pressure | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(m_a\) | - | atomic mass | - | - | - | - |
| \(m_u\) | - | atomic mass constant | \(lbm\) | \(kg\) | \(kg\) | \(1.660\;539\;066\;60\;(50)\;x\;10^{-27}\) \(kg\) |
| \(u\) | - | atomic mass unit | \(lbm\) | \(kg\) | \(kg\) | - |
| \(Z\) | - | atomic number | dimensionless | - | ||
| \(N\) | - | atomic number density | - | \(\large{\frac{atoms}{cm^2}}\) | \(atoms-cm^{-2}\) | - |
| \(A\) | - | atomic weight | - | - | - | - |
| \(p_a\) | - | atmospheric pressure | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(p_a\) | - | atmospheric pressure of moist air | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(T_a\) | - | atmospheric temperature | \(F\) | \(C\) | \(x+273.15\;K\) | - |
| \(A\) | - | Atwood number | dimensionless | - | ||
| \(Nv\) | - | Avagadro's number | moles | moles | moles | - |
| \(\Phi\) | Phi | availability function | - | - | - | - |
| \(\bar {a}\), \(\;a_a\) | - | average acceleration | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) | \(m - s^{-2}\) | - |
| \(\bar {\alpha} \) | alpha | average angular acceleration | \(\large{\frac{deg}{sec^2}}\) | \(\large{\frac{rad}{s^2}}\) | \(rad - s^{-2}\) | - |
| \(v_a\), \(\;\bar{\omega}\) | omega | average angular velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(v_a\), \(\;\bar{\omega}\) | omega | average angular velocity change in velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(\bar {F}\), \(\;F_a\) | - | average force | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(mw\) | - | average mole rate | - | - | - | - |
| \(\bar {u}\), \(\;v_a\) | - | average speed | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(\sigma_{avg}\) | sigma | average stress of weld | \(\large{\frac{lbf}{in^2}}\) | \(Pa\) | \(kg- m^{-1}-s^{-2}\) | - |
| \(\bar {v}\), \(\;v_a\) | - | average velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(\bar{v}\) | - | average velocity change in velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| \(v_a\) | - | average axial velocity of water flow | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) | \(m - s^{-1}\) | - |
| - | - | Avogadro's law | \(mol\) | \(mol\) | \(mol\) | - |
| \(L\), \(\;N_a\) | - | Avogadro constant | \(\large{\frac{count}{mol}}\) | \(\large{\frac{count}{mol}}\) | \(count - mol^{-1}\) | \(6.022\;141\;29\;(27) \;x\; 10^{23}\) \(\large{\frac{count}{mol}}\) |
| \(D_a\) | - | axial diffusivity | - | - | - | - |
| \(P\) | - | axial force | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(P\) | - | axial load | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(k\) | - | axial stiffness | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(F\) | - | axial thrust | \(lbf\) | \(N\) | \(kg - m - s^{-2}\) | - |
| \(\epsilon_a\), \(\;\epsilon\) | epsilon | axial strain (longitudinal strain) | \(\large{\frac{in}{in}}\) | \(\large{\frac{mm}{mm}}\) | \(mm - mm^{-1}\) | - |
| Symbol | Greek Symbol | Definition | English | Metric | Value | |
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
