You are analyzing a scenario where two blocks are placed on a surface, Block A has a mass of 5 kg and Block B has a mass of 0.4 kg. Both blocks experience different frictional forces against the same surface. Classify the following statements into correct categories regarding their friction coefficients: 1) The friction coefficient of Block A is greater than that of Block B. 2) The frictional force on Block B can be considered negligible compared to Block A. 3) The friction coefficient depends solely on the mass of the block. 4) The surface material affects the friction coefficient regardless of mass. Which statements belong to the category of 'Correct Understanding of Friction Coefficients'?

Statement 2 is correct because friction force equals the coefficient multiplied by the normal force, so a lighter block has a smaller friction force and can be ignored. Other options are incorrect because Statement 1 is wrong because the friction coefficient depends on the surfaces, not on how heavy the block is; Statement 3 is wrong because mass does not set the friction coefficient.