Problem 5.215

A beam of monochromatic light passes through a pile of \(N=5\) identical plane-parallel glass plates each of thickness \(l\) \(=0.50 \mathrm{~cm} .\) The coefficient of reflection at each surface of the plates is \(\rho=0.050 .\) The ratio of the intensity of light transmitted through the pile of plates to the intensity of incident light is \(\tau=0.55\). Neglecting the secondary reflections of light, find the absorption coefficient of the given glass.