Weight – Natural sciences – Physics
We explain what weight is and the difference between weight and mass. Also, what are its different meanings and some examples?
What is weight?
The word “weight” comes from the Latin term pens. This concept can be defined as the force with which the planet Earth attracts bodies. However, the word «weight» can be interpreted differently, depending on the discipline from which it is treated.
From physics, weight is understood as the force exerted by a specific body on the point where it is supported. This concept finds its origin in the acceleration of gravity.
The weight of a particular body is calculated as the multiplication of its mass and acceleration due to gravity. The unit in which weight is expressed in the International System of Units is the Newton, commonly abbreviated with the letter N. The team called kilogram/force is used within the technical system, usually abbreviated as Kgf.
What is the difference between weight and mass?
From physics, it is elementary to distinguish two concepts that are often confused or used as synonyms: mass and weight.
Weight is the force that the Earth exerts on a mass. It is not a particular property of bodies but depends on the gravitational field in which they are found. A body does not weigh the same on Earth as on the Moon since the acceleration of gravity is different in each star.
Mass is the amount of matter that a body possesses. The mass of a body is the same on the planet Earth and the Moon.
How is each measured?
Mass is measured in kilograms, and a balance is used for it.
The weight is measured in newtons, and a dynamometer is used.
Weight varies according to latitude and altitude. The mass, however, is constant since it does not depend on external factors such as gravitational force.
So, we usually call weight, such as when we weigh ourselves on a scale and see how many kilos our body weighs, we are talking about mass, not weight. However, this is not important since, in reality, there would be no significant differences; they are directly proportional.
In chemistry, reference is made to the atomic weight, defined as the ratio of the average mass of the atoms of an element to one-twelfth of the group of a carbon-12 atom. This weight will be an average of the consequences of the different isotopes of the same stuff.
In sports, more precisely in boxing, weight is used as a property to make distinctions in the categories of competitors. Some examples are flyweight, in which competitors weighing less than 51 kilograms; featherweight, where athletes weighing less than 57 kg can compete; lightweight, whose competitors cannot exceed 60 kilograms, heavyweight, where athletes must weigh less than 91 kg and the super heavyweight, which are those competed that exceed 91 kg, among many other intermediate categories.
Another different way of using the term peso is in the name given to specific coins. There are several countries, just under a dozen, where they call their legal currency “peso.” The coins of these countries have different values; they only have their common origin, the old Spanish money.
Other uses of the word weight
First, the word weight refers to a scale used for weighing. For example, the lever principle with a sliding counterweight is used in a beam balance to provide credit.
It can also be considered weight to a person’s responsibility, burden, or concern about a situation.
We also speak of weight concerning its importance or influence concerning an issue, a person, or an object.
The specific weight of an object is the weight of that object relative to its volume.
Atomic weight is the average mass of the atoms in a given element.
Molecular weight indicates the sum of the atomic weights that make up a compound.
When we talk about a product, we can refer to the gross weight, the total weight together with its wrapper, box, or container, or the net weight, without any of that.
A merchant ship’s deadweight is the maximum weight load it can carry.
For humans, weight refers to a matter of body mass related to development and health status.
The currency used in certain Latin American countries, including Argentina, Chile, Mexico, and Uruguay, is called the peso.
In sports, the word weight refers to the categories of boxing fighters and other types of hand-to-hand fighting.
