|
Selected Constants | |
Speed of light (vacuum) |
\( c=299792458~m/s \) |
Speed of sound (air at STP) |
\( v=343~m/s \) |
Avogadro constant |
\( N_A = 6.02214076 \times 10^{23} ~ mol^{-1} \) |
elementary charge |
\( e = 1.602176634 \times 10^{-19} ~ C \) |
Planck's constant |
\( h = 6.62607015 \times 10^{-34} ~ J \cdot s \) |
vacuum electric permittivity |
\( \epsilon_o = 8.8541878128 \times 10^{-12} ~ F \cdot m \) |
electron mass |
\( m_e = 9.1093837015 \times 10^{-31} ~ kg \) |
proton mass |
\( m_p = 1.673 \times 10^{-27} ~ kg \) |
photon energy |
\( E = hf = hc/\lambda \) |
photon momentum |
\( p = E/c = hf/c = h/\lambda \) |
Diffraction: