We almost always determine mass by measuring weight. Weight is the force on an object exerted by a gravitational field, and is proportional to the mass. On the Earth's surface, W = m*g, where W is weight, m is mass, and g is the acceleration due to gravity. We can convert weight to mass if our measuring scale is calibrated, usually with an object of known mass.
There are different methods and tools used to measure mass:
- Using a balance: This is the most common method for measuring mass. It works by comparing the unknown mass with a known mass.
- Using a scale: Scales, like the ones found in grocery stores or bathrooms, measure weight. They can then be used to calculate mass by using the relationship between weight and mass.
- Using a load cell instrument: Load cell instruments are used to measure the force exerted by an object. This force can then be converted to mass using the relationship between force, mass, and acceleration.
- Using a spring scale: This is another method that measures weight, and by knowing the acceleration due to gravity, we can convert weight to mass.
The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g).
