Incident Radiation (Part 2)

Electricity and Magnetism Level 4

In the \(xyz\)-coordinate system, a thin solid square of side length \(S\) lies in the \(xy\)-plane with its center at the origin. An isotropic light source is positioned at \((x,y,z) = \left(0,0,\frac{S}{2}\right)\).

What percentage of the light energy is incident on the square \((\)to one decimal place; i.e., \(66\frac{2}{3}\%\) would be entered as 66.7\()?\)