What is the relationship between mass and volume for density?

Density is the ratio of mass to volume for a substance.

In more detail, density is a measure of how much mass is contained in a given volume. It is calculated using the formula:

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

This means that if you know the mass of an object and its volume, you can determine its density by dividing the mass by the volume. The units of density are typically kilograms per cubic metre (kg/m³) or grams per cubic centimetre (g/cm³).

For example, if you have a block of wood with a mass of 200 grams and a volume of 250 cubic centimetres, you can find its density by dividing 200 grams by 250 cubic centimetres, which gives you 0.8 g/cm³. This tells you that each cubic centimetre of the wood has a mass of 0.8 grams.

Understanding density is important because it helps us identify substances and understand their properties. For instance, if you have two objects of the same volume but different masses, the one with the greater mass will have a higher density. This concept is why some objects float in water while others sink. Water has a density of 1 g/cm³, so objects with a density less than this will float, while those with a higher density will sink.

In practical terms, density is used in various fields such as material science, engineering, and even cooking. For example, knowing the density of a material can help engineers design structures that are both strong and lightweight. Similarly, in cooking, understanding the density of ingredients can affect the texture and consistency of a dish.

By grasping the relationship between mass, volume, and density, you can better analyse and predict the behaviour of different materials in various contexts.