We are often confused with the words mass and weight which are seemed to be similar but there’s a lot of difference between them. let us have a detailed explanation about the difference between mass and weight.
What is Mass?
It is one of all the basic quantities in Physics and also the most elementary property of matter. Mass is solely the measure of the quantity of matter in a body. Mass is denoted by “M”. The SI unit of mass is Kilogram (Kg). Mass is usually constant for a body and there are several formulas to calculate mass.
One way to calculate mass is:
Mass = volume × density
The mass may be a base quantity. Mass only has magnitude and then, it’s a scalar quantity. Mass doesn’t rely on gravity and is constant. Mass can never be zero. Mass is often easily measured using any ordinary balance like beam balance, lever balance, pan balance, etc.
Weight, though related to mass, nonetheless differs from the latter. Weight essentially constitutes the force exerted on the matter by the gravitational attraction of Earth, and so it varies slightly from place to place. In contrast, mass remains constant regardless of its location under ordinary circumstances. A satellite launched into space, for example, weighs increasingly less the farther it travels away from Earth. Its mass, however, stays the same.
What is Weight?
Weight is that the measure of the quantity of force performing on a mass due to acceleration due to gravity. Weight is denoted by “W”. The SI unit of weight is Newton (N). Weight is that the measure of the gravitational force performing on a body. Weight will be calculated from the subsequent formula:
Weight = mass × acceleration due to gravity
Weight could be a derived quantity. Weight has both magnitude and direction (towards the middle of gravity) and so, it’s a vector quantity. Weight relies on gravity then, it varies from place to place. Weight may be zero where there’s no gravity (like space). Weight may be measured by a spring balance or by using its formula.
The kilogram is the SI unit of mass and it is the almost universally used standard mass unit. The associated SI unit of force and weight is the Newton, with 1 kilogram weighing 9.8 Newtons under standard conditions on the Earth’s surface. However, in the US common units, the pound is the unit of force (and therefore weight). The pound is the widely used unit for commerce. The use of the pound-force constrains the mass unit to an inconveniently large measuring unit called a “slug”. The use of this unit is discouraged, and the use of exclusively SI units for all scientific work is strongly encouraged.
What is a Slug?
The slug is the unit of mass in the US common system of units, where the pound is the unit of force. The pound is therefore the unit of weight since weight is defined as the force of gravity on an object. While the pound-force and pound weight is the widely used units for commerce in the United States, their use is strongly discouraged in scientific work. The standard units for most scientific work are the SI units
you can check Difference Between Force and Pressure also
Difference between mass and weight
| Mass | Weight |
|---|---|
| Mass is simply the measure of the amount of matter in a body. | Weight is the measure of the amount of force acting on a mass due to acceleration due to gravity. |
| Denotation | |
| Mass is denoted by “M”. | Weight is denoted by “W”. |
| Unit of Measurement | |
| The SI unit of mass is Kilogram (Kg). | The SI unit of weight is Newton (N). |
| Formula | |
| Mass is always constant for a body and there are several formulas to calculate mass. One way to calculate mass is: Mass = volume × density | Weight is the measure of the gravitational force acting on a body. Weight can be calculated from the following formula: Weight = mass × acceleration due to gravity |
| Quantity Type | |
| Mass is a base quantity. Mass only has magnitude and so, it is a scalar quantity. | Weight is a derived quantity. Weight has both magnitude and direction (towards the center of gravity) and so, it is a vector quantity. |
| Measuring Instrument | |
| Mass can be easily measured using any ordinary balance like beam balance, lever balance, pan balance, etc. | Weight can be measured by a spring balance or by using its formula. |
| Gravitational Effect | |
| Mass does not depend upon gravity and is constant everywhere. Mass can never be zero | Weight is dependent on gravity and so, it varies from place to place. Weight can be zero where there is no gravity (like space) |
Relation Between Weight and Mass
Consider a body having an outsized mass and huge weight. An example of this example may be a large object which is tough to throw because the burden of this object is large.
Therefore, the relation between weight and mass will be derived with the assistance of Newton’s second law which explains that the free-falling object has an acceleration “g” because of the magnitude.
If an object with a mass of 1kg falls with an acceleration of 9.8 m.s-2, then the magnitude of the force is given as :
F = ma
= (1kg)(9.8m.s-2)
= (9.8 kg.m.s-2)
= 9.8N
Therefore, it is concluded that the relation between weight and mass of an object with 1kg mass will have a weight of 9.8N.
