If you’ve ever used a balance, then you know that it compares objects’ weights to determine their mass. While this type of scale does depend on gravity, the resulting measurements remain the same on different planets.
This is because mass does not change with the gravitational pull of a planet. But, how do we measure mass exactly?
How is mass measured?
The most common method for measuring mass is with a balance. This is a scale that compares the unknown object to a known one and gives the value of the unknown in terms of the values of the known objects (masses). Balances work just as well on Earth as they do in space or places with no gravity because changes in the strength of gravity are distributed equally between both sides of the balance.
Encourages Critical Thinking: Students have to think about the size, shape, and material of each item as they estimate its mass. This helps them to develop a deeper understanding of the relationship between an object’s mass and its force of acceleration.
Students also record their measurements in both grams and kilograms on the worksheet, giving them practice converting between these two units of measurement and solidifying their knowledge of both. This helps them become more comfortable using a scale and confident in their abilities to measure and identify objects in the real world.
How is it used in science?
The standard unit for mass is the kilogram (kg), abbreviated kg. This is one of the seven SI base measurement units. Scientists use a variety of laboratory balances to measure mass. These instruments are highly accurate and help to advance scientific knowledge.
A key concept in science is that matter is everywhere. This is why mass measurements are so important. Every object is made up of atoms and has a unique makeup that determines its mass. Whether you are buying groceries, taking medication, designing a bridge or space shuttle, or trading goods – the importance of mass measurement is apparent in all that we do.
The most common way to measure mass is by using a balance. An unknown object is contrasted with a known estimation of mass, and the result gives us its value. NIST maintains a set of secondary stainless steel kilogram standards that are calibrated through hydrostatic weighing with silicon reference masses [1]. This allows for high accuracy in the measurement of the density of an unknown object.
How is it used in industry?
The ability to measure force and mass is critical in most industries. In manufacturing it is used for calibration of testing machines, quality control in factories, and ensuring product consistency. In transportation it is used to ensure safety for cargo and vehicles.
NIST has facilities and measurement capabilities to calibrate many types of equipment including electronic mass comparators, mechanical balances, and hydrostatic weighing systems. It also has a variety of tools to determine volumes and densities of standards. These include the immersed balance technique and the patented NIST hydrostatic weighing system. Both of these techniques require that the standard be immersed in a fluid. NIST has a number of different bath designs to prevent contaminating the standard with water or other liquids.
Because the kilogram is defined by an artifact, it can be damaged by environmental effects and wear on its surface. The BIPM has developed recommended cleaning practices for platinum-iridium (Pt-Ir) prototype kilograms to reduce the potential for contamination. These are incorporated into NIST’s yearly maintenance of the system and are monitored by Pt-Ir check standards incorporated into each measurement series.
How is it used in everyday life?
Mass measurement is very common in everyday life, from weighing food for cooking to determining the volume of liquids. It is also used to compare the inertia of different objects (e.g., a lorry has more inertial mass than a car).
In order to correctly measure the mass of an object, you need a balance calibrated with a known value of mass. This method works both on Earth and in space, since the unknown object’s weight on the balance is compared with the mass of the balanced standard.
You can teach children the basics of measuring mass by letting them compare the weight of small and large objects like pens and bottles of water. Taking a hands-on approach will help kids develop an intuitive understanding of this important concept, which will allow them to effortlessly grasp more complicated mathematical and physics concepts later in life. Download our free “Measuring Mass” worksheet to get started.