Formula Symbols - R

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

For other symbols see:  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

See Dimensionless Numbers, General Constants

SymbolGreek SymbolDefinitionUSMetric
\(L\) - radiance - -
\(r\) - radial distance \(ft\) \(m\)
\(Q_e \;,\; W\) - radiant energy - -
\(w\) - radiant energy density - -
\(M\) - radiant exitance - -
\(P \;,\; \Phi\) Phi radiant flux - -
\(\phi\) phi radiant flux density - -
\(I\) - radiant intensity - -
\(P \;,\; \Phi\) Phi radiant power - -
\(Q_r\) - radiant heat - -
\( r\) - radius \(in\;\)or\(\;ft\) \(m\)
\(\rho\) rho radius of curvature \(in\) \(m\)
\(k\) - radius of gyration \(ft\) \(m\)
\(R\) - range \(ft\) \(m\)
\(k\) - rate coefficient - -
\(r\) - ratio - -
\(k\) - ratio of specific heat - -
\(a\) - ratio of transformation - -
\(Ra\) - Rayleigh number dimensionless number dimensionless number
\(X\) - reactance - -
\(R\) - reaction \(lbf\) \(N\)
\(Q\) - reaction energy - -
\(R\) - reaction force \(lbf\) \(N\)
\(\alpha\) alpha recombination coefficient - -
\(z\) - reduced activity - -
\(\mu\) - reduced mass - -
\(p_r\) - reduced pressure - -
\(\upsilon_r\) upsilon reduced specific volume - -
\(T_r\) - reduced temperature - -
\(\eta_r\) eta reduced viscosity - -
\(\rho\) rho reflectance - -
\(\tau\) tau reflection coefficient - -
\(\rho\) rho reflectivity - -
\(RF\) - reheat factor - -
\(x\) - relative abundance - -
\(a\) - relative activity - -
\(A_r \;,\; M_r\) - relative atomic mass - -
\(RD \;,\; d\) - relative density dimensionless number dimensionless number
\(RH \;,\; \phi \) phi relative humidity - -
\(M_r\) - relative molar mass - -
\(\mu_r\) mu relative permeability - -
\(K\) - relative permittivity - -
\(\alpha \;,\; \alpha_p\) alpha relative pressure coefficient - -
\(k\) - relative roughness \(in\) \(mm\)
\(\eta_r\) eta relative viscosity - -
\(E_r\) - relativistic energy - -
\(m_r\) - relativistic mass - -
\(p\) - relativistic momentum - -
\(\tau\) tau relaxation time - -
\(F_r\) - removal factor - -
\(\rho_r\) rho residual resestivity - -
\(R \;,\; \Omega\) omega resistance \(ohm\) \(ohm\)
\(\rho\) rho resistivity - -
\(R\) - resultant force \(lbf\) \(N\)
\(Re\) - Reynolds number dimensionless number dimensionless number
\(F_R\) - Reynolds number factor - -
\(A\) - Richardson constant - -
\(Ri\) - Richardson number dimensionless number dimensionless number
\(R\) - rigidity - -
\(C_{rr}\) - rolling resistance dimensionless number dimensionless number
\(Ro\) - Roshko number dimensionless number dimensionless number
\(Ro\) - Rossby number dimensionless number dimensionless number
\(J \;,\; K\) - rotational - -
\(\alpha\) alpha rotational acceleration \(rad \;/\; sec^2\) \(rad \;/\; s^2\)
\(C_r\) - rotational dampening coefficient \(ft-lbf-sec \;/\; rad\) \(N \cdot m \cdot s \;/\; rad\)
\(\tau\) tau rotational force - -
\(n\) - rotational speed \(rpm\) \(rpm\)
\(k_r\) - rotational spring constant \(ft-lbf \;/\; rad\) \(N \cdot m \;/\; rad\)
\(F\) - rotational term - -
\(\omega\) omega rotational velocity \(rad \;/\; sec\) \(rad \;/\; s\)
\(R_{\infty}\) infty Rydberg constant constant constant