At various times in our lives we have come across situations in which we had to distinguish between direction and meaning. Many people believe that it is the same thing, but this is not true. In our studies in Physics, especially in studies on vector kinematics, we are constantly faced with these determinations. Let's take a basic example: imagine that you are traveling in a car on a road towards the northeast coast in search of a good vacation. If a loved one of yours comes to your house and asks for you, your parents will surely answer that you went to the beach.
In physical terms we can say that this information is not enough, as we really want to know where you are located or where you will be after a few hours of travel. For this, we use the direction and sense quantities in order to facilitate its location. In the statement of this example we can remove the notions of direction and meaning, which are actually hidden, but present. Let's see then.
The most informative answer your parents could give would be the following: he (a) went in this direction (he would probably be showing with the arm extended horizontally) and in this direction (with the index finger it would be indicating the direction, for example, east to West). Therefore, we can assign the term
direction whenever we are dealing with: horizontal direction, vertical direction, circular direction. the term sense will be being employed in: right to left, or left to right, bottom to top, top to bottom, counterclockwise, clockwise.Do not stop now... There's more after the advertising ;)
It is necessary to know that physical quantities can be divided into two groups: scalar and vector. Therefore, quantities such as length, mass and time are examples of scalar magnitudes. For example, if the mass of a book is 200 grams or if a class lasts 50 minutes, these two numerical values, accompanied by the respective units of measurement, are enough to provide us with a complete idea of each of these physical magnitudes.
On the other hand, the vector quantities, in addition to a numerical value accompanied by a unit, require direction and sense to be determined. For example, just the information that your school is 400 meters from your home is not enough for a person to locate you. It is necessary to provide, in addition to distance, the direction and direction that the person should take to get to school.
Vector quantities are represented by an oriented straight line segment called a vector. Thus, we say that a vector has three characteristics: module, direction and direction.
By Domitiano Marques
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
SILVA, Domitiano Correa Marques da. "Important Notions"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/nocoes-importantes.htm. Accessed on June 27, 2021.
