Inquisitive children are ready to learn at any age, and early exposure to physics concepts like mass can help them effortlessly understand subjects like mathematics and chemistry later. Mass is a property of matter that doesn’t change if the body changes shape or location.
A balance is the most common device for mass measurement, and it works in locations with and without gravity to measure objects equally.
Definition
Mass is the amount of matter in an object or particle. It is the most fundamental property of matter, and it does not change.
Measuring mass is usually done using a balance. An unknown mass is compared to a known value of mass and the difference between the two is the measured mass. Balances can be used in places with gravity or without it since changes in the strength of the gravitational field affect both masses on the balance equally.
The terms weight and mass are often confused. However, they are different physical properties. Weight is a measure of the effect of gravity on something, while mass is a measurement of the amount of matter that something has. An elephant and a mouse may be the same size, but an elephant has much more matter inside it than a mouse, so it has more mass. This difference in matter is why a person’s weight may differ when they go to another planet: the gravitational force is different, but their mass remains the same.
Units
The unit used to measure mass is the kilogram, kg. It is part of the metric system and is also commonly used in non-metric systems, such as the avoirdupois pound (used in the United States Customary and Imperial systems of units).
The kilogram along with the meter, second, ampere, kelvin, and mole are known as SI base units. The base units are defined in terms of the physical quantity of the International Prototype Kilogram, a golfball-sized platinum-iridium cylinder kept at NIST.
Other units for quantities like the liter for volume are called derived units because they are obtained by multiplying or dividing the SI base units. Derived physical quantities are also defined in terms of these units. A coherent system of units is one where the base units and derived units are consistent with each other. In such a system, 1 kilogram is equal to 1 kilogram per square centimeter. This page is based on a Wikipedia article, and as such it may not have been reviewed by professional editors.
Calculation
While the terms “weight” and “mass” are often used interchangeably, they refer to different measurements of heaviness. Mass is a measurement of the amount of matter contained in an object, while weight is based on the gravitational force that objects exert on one another.
In order to calculate an object’s mass, you must first have information on its density and volume. Density is the amount of matter per unit area and can be found through a formula, such as mass = density / volume. Volume is the amount of space an object occupies and can be measured in units like cubic meters i.e. m3 for solids or cubic centimeters i.e. cm3 for liquids.
The most common method of measuring mass is using a balance. This allows you to compare the unknown object’s mass to a known value of an existing sample, eliminating variables such as gravity. Balances are expensive and delicate instruments, so they must be treated with care.
Interpretation
The interpretation of mass measurement requires consideration of the statistical background. The normal distribution of mass data is not always appropriate, especially for very small or varying samples. A good understanding of this is crucial for the use of statistical tests and for the evaluation of precision, which is a function of sample variability.
Mass spectrometry literature often uses a number of terms that describe the statistics of accurate mass measurements. This confusion can lead to misunderstandings. A good source of information is the IUPAC definitions and descriptions of terminology used in mass spectrometry.
The most basic concept of matter is that it has mass. But a greater amount of matter does not necessarily mean a greater weight (although it will). Rather, an object’s mass is determined by its density and volume, and it is its acceleration — observed when it is subjected to the force of gravity — that determines its weight. The same principle applies to a weighing scale.