DUPL Quantity (Units) PHYSICAL CONSTANTS Best Experimental Symbol Value Approximate Value for Problem Work Permittivity of free space (F/m) e u Permeability of free space (H/m) /j, o Intrinsic impedance of free rj o space (fl) Speed of light in vacuum (m/s) c Electron charge (C) e Electron mass (Kg) m Q Proton mass (kg) m p Neutron mass (Kg) m a Boltzmann constant (J/K) K Avogadro's number (/Kg-mole) N Planck's constant (J • s) h Acceleration due to gravity g (m/s 2 ) Universal contant of gravitation G (m 2 /Kg • s 2 ) Electron-volt (J) eV 8.854 x 10 12 4i7 x 10" 7 376.6 2.998 x 10 8 -1.6030 x 10" l9 9.1066 x 10" 31 1.67248 x 10" 27 1.6749 x 10" 27 1.38047 x 10" 23 6.0228 x 10 26 6.624 x 10" 34 9.81 6.658 x 10-" 1.6030 x 10" 19 12.6 x 10" 7 120ir 3 X 10 8 -1.6 x 10" 19 9.1 x 10" 31 1.67 x 10" 27 1.67 x 10 27 1.38 x 10" 23 6 x 10 26 6.62 x 10" 34 9.8 6.66 x 10" 11 1.6 x 10" 19