As shown in the figure, a and B are two cubes, and their density ratio is 1:3. Place a and B on the horizontal table, and the pressure on the table is equal If the pressure of a on the table is FA and PA after B is placed on a, and the pressure of B on the table is FB and Pb after a is placed on B, then the ratio of FA to FB is_ The ratio of PA to Pb is

As shown in the figure, a and B are two cubes, and their density ratio is 1:3. Place a and B on the horizontal table, and the pressure on the table is equal If the pressure of a on the table is FA and PA after B is placed on a, and the pressure of B on the table is FB and Pb after a is placed on B, then the ratio of FA to FB is_ The ratio of PA to Pb is

Let the edge length of a be a and the mass be m [a]; let the edge length of B be B and the mass be m [b] (Let G be the local gravity acceleration); then the bottom area of a is a ^ 2 and the total pressure of the bottom surface is m [a] g / (a ^ 2); the volume is a ^ 3 and the density is m [a] / (a ^ 3); the bottom area of B ^ 2 and the total pressure of the bottom surface is m [b] g / (b ^ 2); the volume is B ^ 3 and the density is m [a] / (a ^ 3)