A cubical vessel has opaque walls. An observer (dark circle in figure below) is located such that sh

A cubical vessel has opaque walls. An observer (dark circle in figure below) is located such that sh - চর্চা

$\mu sin \, i = 1 \times sin 45^o$

$\dfrac{4}{3} sin \, i =\dfrac{1}{\sqrt{2}}$

$\dfrac{4}{3} \dfrac{y-10}{\sqrt{(y-10)^2+y^2}}=\dfrac{1}{\sqrt{2}}$

$y=27$ (approximate calculation)