# Formula Symbols - U

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

SymbolGreek SymbolDefinitionUSMetric
$$R$$ - universal gas constant $$ft-lbf/lbmol-^\circ R$$ $$J/kmol\cdot K$$
$$G$$ - universal gravitational constant $$ft/sec^2$$ $$m/s^2$$
$$U$$ - Ursell number dimensionless number dimensionless number