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The concept of apparent mass is centered around the idea of how an object's mass changes when it is submerged in a fluid. Apparent mass refers to the weight an object seems to have when it's lifted under water or any liquid other than air. This feels less than its actual mass because of the buoyant force, which counteracts some of the object's weight.
To calculate apparent mass, you subtract the buoyant force exerted by the liquid on the submerged object from the object's actual mass. It's important to note:

• The buoyant force is equal to the weight of the fluid displaced by the object.
• In our example, the cube's apparent mass in water was 47.3 g, and it became 45.22 g when submerged in glycerin due to differences in buoyancy.

This alteration in mass gives an illusion that the object weighs less, when in reality, it stays the same.

Specific gravity is a concept used to compare the density of a substance to a reference substance, usually water for liquids and solids. It helps us understand how dense a fluid is compared to another. If a liquid has a specific gravity greater than 1, it's denser than water.
In the exercise, glycerin has a specific gravity of 1.26. This means glycerin is 1.26 times denser than water. Specific gravity is calculated with the formula:

• Specific Gravity = Density of Substance / Density of Water

Recognizing specific gravity helps to foresee how the buoyant force will change when an object is submerged in different fluids. A higher specific gravity indicates a stronger buoyant force. This was evident when the object switched from water to glycerin.

Density is a fundamental concept that determines how much mass is contained in a given volume. It is expressed as mass per unit volume and is crucial when calculating buoyant forces and understanding specific gravity.

• The density formula is: \[\text{Density} (\rho) = \frac{\text{Mass}}{\text{Volume}}\]
• In the exercise, the density of glycerin was calculated using its given specific gravity: \[1.26 \text{ g/cm}^3 = 1.26 \times 1 \text{ g/cm}^3\]

Understanding density helps explain why objects float or sink, and assists in assessing the apparent mass in different fluids. It's a core concept in studying buoyancy and helps clarify how different materials interact with each other when placed in a fluid.