As mentioned earlier, physical quantities (or dimensions) are measurable variables. This means they have size, or magnitude.
However, many quantities also include a direction component. Because of this, we classify physical quantities into two categories:
- SCALAR: Quantities that have magnitude only.
- VECTOR: Quantities that have both magnitude and direction.
Some common examples of scalar quantities include time, energy, area, distance, and speed.
Some common examples of vector quantities include displacement, velocity, force, and magnetic field.
Vectors are represented visually as arrows. The length of the arrow is proportional to the magnitude of the physical quantity it represents, while the orientation of the arrow indicates its direction.
This means that even if two arrows have the exact same length, they represent completely different vectors if they point in different directions.
Watch the video to learn more about vectors, how they are represented, and how to add them.
Use the following interactive to explore vector addition
The first button explore vectors in a rectilinear fashion
The second button explore vectors in a 2D fashion