How do you calculate the density of a fluid?

The correct method for calculating the density of a fluid is to divide the mass of the fluid by its volume. Density is defined as the amount of mass contained in a unit of volume, and this relationship is expressed through the formula:

[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} ]

This formula allows you to determine how compact or concentrated the mass of the fluid is relative to the space it occupies. Understanding density is crucial in various engineering and scientific applications, such as buoyancy calculations, fluid dynamics, and material selection.

In contrast, other methods presented do not accurately define or calculate density. For instance, multiplying volume by pressure does not yield a measure of density but rather relates to other physical quantities like pressure-volume work. Summing mass and volume would not give a useful measure for density, as density requires a ratio, not an addition of these two distinct properties. Additionally, measuring the weight of the fluid relates to gravitational force acting on it, rather than directly calculating density, which involves mass and volume.