A point light source radiating light isotropi cally delivers a power P $=53\mathrm{.}1$ W$.$ A mir ror is placed at point B$,$ which is a distance r $=2\mathrm{.}65$ m away. The mirror has a cross sec tion of A $=2\mathrm{.}54$cm$2$ andisatotallyreflecting surface. B r Determine the light intensity I at point B$.$ Make the approximation that all the light hitting the mirror comes in perpendicular to it