To most people, the terms Mass and Weight are used interchangeably and mean the same thing and are both equal. It might be challenging to understand, but mass and weight are actually different. The difference between mass and weight is that mass is the amount of matter in a material, while weight is a measure of how the force of gravity acts upon that. In this article, we will discuss the differences in more detail.
Definition of Mass
All objects are made up of Atoms. Mass is a physical quantity that indicates the total amount of matter (the density of atoms) or substance that an object is made up of. In physics there are different ways of determining the quantity of mass – Inertial mass and gravitational mass. – Inertial mass is determined by how much the object resists acceleration. For example, if you push two objects under the same conditions with the same amount of force, the object with the lower mass will accelerate faster. Gravitational mass is a measurement of how much gravity an object exerts on other objects. It can also be the measurement of how much gravity an object experiences from another object.
When it comes to your mass, it’s constant. Mass is often measured by how much an object weighs, however, it is not weight because it remains the same, irrespective of the location of the object. Your mass on Earth is the same as it is on the sun or Jupiter. The mass of an object is constant.
The internationally recognised unit of mass is kilogram (kg). However, there are also other units of measurements such as gram, milligram, tonnes or ounces and pounds. When somebody is asked their weight, almost always the response will be in kilograms or pounds, however, this is technically incorrect and is an expression of their mass, not weight.
Definition of Weight
Weight is different from mass. Weight is the force exerted by an object when acted on by a gravitational field. It can be variable as the weight of an object can change in relation to how far and near it is to the Earth’s centre. It is possible that an object has a different weight at different points of Earth. If you are on a Mountain it may be possible that your weight can be slightly less than the weight on the ground level of Earth. The mass of an object will never change, but the weight of an item can change based on its location. For Example, in space, there is no gravity so objects float about and register zero weight. However, the objects continue to have mass and extra effort is required by the astronauts to hold down the objects or to move them about.
Key Differences Between Mass and Weight
The differences between mass and weight can be drawn clearly on the following grounds:
| MASS | WEIGHT | |
| 1. | Mass is a measurement of the amount of matter in an object. | Weight depends upon the effect of gravity. |
| 2. | It is a scalar quantity, therefore, has magnitude only. | It is a vector quantity, therefore, has both magnitudes as well as direction. |
| 3. | The mass of an object is the same everywhere. | The weight of an object changes depending on the magnitude of the gravity. |
| 4. | It does not change according to the location. | It varies according to the location. |
| 5. | It can never be zero. | It can be zero, such as in space. |
| 6. | The SI unit of mass is the kilogram (kg). | The SI unit of weight is Newton (N). |
| 7. | Mass is represented by “m”. Its formula is m = w/g | Weight is represented by “W”. Its formula is W = mg |
| 8. | Mass is measured by using an ordinary or beam balance. | Weight is measured by using a spring balance. |