A vertical shaft of light from a projector forms a light spot S = 100 cm2 in area on the ceiling of a round room of radius R = 2.0 m. The illuminance of the spot is equal to E = 1000 lx. The reflection coefficient of the ceiling is equal to p = 0.80. Find the maximum illuminance of the wall produced by the light reflected from the ceiling. The reflection is assumed to obey Lambert’s law.