To measure the density of a substance, its mass and volume has to be determined. So that for the milk in the carton, its mass and volume should be known. Also for the two objects, their mass and volume has to be determined.
Density of a substance (ρ) is the rate of the mass (m) of the substance to its volume (V). It is measure in kg/
.
i.e ρ = 
The density of a substance can be determined once the mass and its volume has been accurately measured.
1. How to measure the density of the contents of a milk carton.
A milk carton has a definite mass and volume so that;
a. Determine the mass of the milk carton with its content.
b. Determine the mass of the milk carton when empty.
c. Subtract the mass of the milk carton when empty from the mass of the carton with its content. This will give the mass of the milk in the carton.
d. Using a beaker, measure the volume of the milk.
e. Divide the mass of the milk by its volume to determine its density.
2. How to measure the densities of two objects of equal mass.
Since the two objects have equal mass, then:
a. Fill an Eureka's can or a beaker with sprout with water to its brim.
b. Slowly drop the mass into the beaker with water so as to collect the volume of the liquid displaced into another beaker.
c. The volume of the liquid displaced is the volume of the mass.
d. Divide the mass of the object by its volume to determine its density.
NB: This procedures is observed to determine the densities of the two object individually.
For more explanations, kindly visit: brainly.com/question/17924956
