Dictionary:Fig A-2

FIG. A-2. Absorption terminology. Sometimes this terminology is used for attenuation because of factors other than absorption. E = energy, ${\displaystyle \Delta E}$ = energy lost in one cycle, ${\displaystyle \lambda }$ = wavelength, f = frequency, x = distance, t = time, ${\displaystyle {\frac {A}{A_{0}}}={\frac {\text{amplitude}}{\text{initial amplitude}}}}$, ${\displaystyle {\frac {A_{1}}{A_{2}}}={\frac {\text{amplitude}}{\text{amplitude one cycle later}}}}$.[1]