We explain what weight is and what the difference is between weight and mass. Also, what are their different meanings and some examples.
What is weight?
The word “weight” comes from the Latin term pensum. This concept can be defined as the force with which the planet Earth attracts bodies. However, the word “weight” can be interpreted in different ways, depending on the discipline from which it is discussed.
From physics, the concept of weight is understood as the force exerted by a certain body on the point on which it is supported. This concept finds its origin in the acceleration of gravity.
The weight of a certain body It is calculated as the multiplication of its mass and the acceleration of gravity. The unit in which weight is expressed in the International System of Units is the Newton, commonly abbreviated with the letter N. Within the technical system, the unit called kilogram/force is used, which is usually abbreviated as Kgf.
See also: Weight measurements
What is the difference between weight and mass?
From physics it is essential to distinguish two concepts that are often confused or used as synonyms, which are 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 on each star.
- Mass is the amount of matter that a body has. The mass of a body is the same on planet Earth and on the Moon.
How is each one measured?
- Mass is measured in kilograms and a scale is used for this.
- Weight is measured in newtons and a dynamometer is used for this.
Weight varies according to latitude and altitude. The mass, on the other hand, is constant since it does not depend on external factors such as the gravitational force.
So, what we normally call weight, such as when we we weigh on a scale and we 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 major differences, they are directly proportional.
In chemistry, reference is made to atomic weight defined as the ratio of the average mass of the atoms of an element to one twelfth of the mass of a carbon-12 atom. This weight will be an average of the weights of the different isotopes of the same element.
In the sporting field, more precisely in boxing, weight is used as property to make distinctions in competitors' categories. Some examples are flyweight, which are competitors weighing less than 51 kilograms, featherweight, where athletes weighing less than 57kg can compete, lightweight, whose competitors cannot exceed 60kg, and heavyweight, where Athletes must weigh less than 91 kg and super heavyweight, which are those competed that exceed 91 kg, among many other intermediate categories.
Another totally different way of using the term weight is in the name given to certain currencies. Currently there are several countries, just under a dozen, where they call their legal currency “peso”. The currencies of these countries have a different value, they only have their common origin, which is the old Spanish currency.
Other uses of the word weight
- First of all, the word weight refers to a balance as a device used to weigh. In a beam balance, for example, the lever principle is used with a sliding counterweight to exert balance.
- It can also be considered a weight responsibility, burden or concern How a person feels about a situation.
- With respect to an issue, a person or an object, we also talk about weight with respect to its importance or influence.
- He specific weight of an object is the weight of said object in relation to its volume.
- He atomic weight is the average mass of the atoms in a given element.
- He 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 that is, the total weight together with its wrapper, box or container, or the net weight, without any of that.
- For a merchant ship, the dead weight It is the maximum weight load it can carry.
- For humans, weight refers to a matter of body mass related to development and health status.
- As currency unit The peso is the currency used in certain Latin American countries, including Argentina, Chile, Mexico and Uruguay.
- In sport, the word weight is used to refer to the categories of boxing fighters and other types of hand-to-hand fighting.
