Mechanics

# Physics in Everyday

We can say that Physics was developed with the purpose of explaining the phenomena of nature, from the most common to the most complex. Therefore, it is quite natural that Physics is directly related to our daily lives. Despite this, it is very common for everyday occurrences to be treated with a language completely different from that used by the scientific community. It’s just a matter of adequacy: some words fit well into popular parlance, while others better fit the technical vocabulary.

You don’t usually say, for example, that you are suffering the effects of a high temperature. Colloquially it just says it’s hot. However, scientifically, heat is energy in transit , so no one can “be” with it. There are other examples in which the distinction between meanings of identical expressions used in different contexts is clear.

Because of these differences between common and scientific nomenclature, many people confuse three words that will be used a lot from now on: mass , weight , and normal . Let’s take a look at the comparison table below:

By analyzing the table, it becomes clear the importance of, at least in Physics, using the expressions mass, weight and normal with some care, so that scientific rigor is not affected. One cannot, for example, say that a person weighs 70 kg. In our discipline, weight is a force, so it must have the newton (N) as a unit of measurement. Thus, it would be correct to say that the person weighs 700 N.

For Physics, when someone gets on a scale, weight is not being measured. Common scales are graduated in kilograms, so they inform the mass of those who climb on them. From now on, there will be a distinction between mass and weight. Remember that this is only valid for a scale that is in a vertical position and in equilibrium.