146. Solving a chemistry problem

1. Using a nephelometer, the turbidity of two hydrasols of mastics of equal concentrations was compared. The turbidity of the determined and standard sols became the same at the heights of the illuminated parts of the first sol
h 1 = 5⋅10 -3 m and the second sol h 2 = 19,0⋅10 -3 m, respectively. Average radius
particles of the standard sol r 1 = 120⋅10 -9 m. Determine the radius of the particles of the second
sol.