Vector diagrams are
diagrams that depict the direction and relative magnitude of a vector quantity
by a vector arrow. Vector diagrams can be used to describe the velocity of a
moving object during its motion. For example, a vector diagram could be used to
represent the motion of a car moving down the road.
In a vector diagram, the magnitude of a vector quantity is
represented by the size of the vector arrow. If the size of the arrow in each
consecutive frame of the vector diagram is the same, then the magnitude of that
vector is constant. The diagrams below depict the velocity of a car during its
motion. In the top diagram, the size of the velocity vector is constant, so the
diagram is depicting a motion of constant velocity. In the bottom diagram, the
size of the velocity vector is increasing, so the diagram is depicting a motion
with increasing velocity - i.e., an
acceleration.
Vector diagrams can be used to represent any vector quantity.
In future studies, vector diagrams will be used to represent a variety of
physical quantities such as acceleration, force, and momentum. Be familiar with
the concept of using a vector arrow to represent the direction and relative
size of a quantity. It will become a very important representation of an
object's motion as we proceed further in our studies of the physics of motion.