Mass is the amount of matter that is contained in any body. In turn, matter is something that can be physically touched and felt. As a rule, the mass is associated with the size of the object, but this is not always true. For example, the globe could be larger, but have less mass. The article addresses the issue of how to find mass through volume and density.
The concept of mass and its appearance in physics
Before considering the question of how to find mass through volume and density, it is necessary to understand where the mass came from in physics, and what it determines. The term "mass" itself comes from the Latin word massa - a lump, substance, body, which, in turn, originates from the Greek word μᾶζα, literally meaning "dough."
Mass is a physical concept that indicates the amount of matter contained in the body. In the International System of Units, it is measured in kilograms. The appearance in physics of this concept is associated with two important laws:
- The law of gravity.
- Newton's second law.
In accordance with the concept of universal gravitation, two bodies are attracted to each other with a force that is proportional to the product of two constant quantities. These constants are called the gravitational masses of these bodies. That is, the gravitational mass of a body is a property of matter itself, due to which all bodies are attracted to each other.
As for Newton’s second law, it should be remembered that any acceleration caused by the action of some external force on a given body is proportional to some constant called an inertial mass. In this law, inertial mass determines the measure of "complexity" of a change in the speed of a given body.
Body volume concept
Volume is a physical property of matter that determines the space it occupies. In the International System of Units, it is measured in cubic meters, but other units of measurement are also often used: cubic centimeters and liters.
Depending on the state of the substance, various methods for measuring volume are used:
- For liquid bodies use special graduated transparent containers (cylinders, test tubes, pipettes and others).
- For solids that retain their shape, volume is measured based on their linear dimensions using the appropriate mathematical formula. For example, a box is equal to the product of its length, width and height.
- Gaseous bodies do not retain their volume, unlike liquids and solids, therefore for gases it is always equal to the volume of the vessel in which the gas is located.
Substance density
Finally, when answering the question of how to find mass through volume and density, one should deal with the last characteristic - the density of bodies. Density is an integral physical characteristic of matter that binds mass and volume, that is, it determines how much mass of a substance is contained in a unit volume. In the International System of Units, it is expressed as kilograms per cubic meter, but is often used in grams per centimeter cubic.
Any substance has a specific density value, for example, one kilogram of mass is contained in one liter of water, that is, its density is 1 kg / l or 1000 kg / m 3 .
The concept of density plays an important role in nature. So, the issue of the buoyancy of bodies in water is exclusively a matter of comparing the density of the body and water. Bodies having a higher density than water are drowning in it, for example, an egg or stone.
How to find mass in physics through volume and density?
We now proceed directly to the solution of the problem. Suppose you want to measure the mass of existing diamond. First you need to measure its volume, for example, it is equal to 5000 cm 3 . Understanding how to find mass through volume, one should also determine the density of a substance. In this case, you can refer to the tabular data and see what density is typical for diamond. In the table we find that it is equal to 3.52 g / cm 3 .
After all the necessary quantities have been determined, one should use the well-known formula how to find the mass through volume and density: m = V * ρ, where V is the volume of the body, ρ is the density. Substituting the obtained values for diamond, we obtain: m = 5000 (cm 3 ) * 3.52 (g / cm 3 ) = 17600.0 g = 17.6 kg. It should be noted that when the volume is multiplied by the density, the units of volume measurement (cm 3 in the example) are reduced and only units of mass remain.