A charged particle moves along the y axis according to the law y = a cos wt, and the point of observation P is located on the x axis at a distance l from the particle (1 >> a). Find the ratio of electromagnetic radiation flow densities S1/S2 at the point P at the moments when the coordinate of the particle yl = 0 and y2 = a. Calculate that ratio if w = 3.3 ∙ 106 s-1 and l = 190 m.