Will it speed up or slow down?
Establish which direction represents + or -
6 5 4 3 2 1 0 1 2 3 4 5 6
Scalar quantities have magnitude only.
Vector quantities have magnitude AND direction
Velocity: speed and direction (20 m/s, North)
Anatomy of a Vector
Vectors should be drawn to scale:
10 m should be twice as long as 5 m
Vectors get added “head to tail”(or “tail to head”)
Adding vectors is the same as connecting them head-to-tail.
A vector contains a magnitude (length of the arrow which is the value of whatever
Adding multiple vectors will give you a single resultant vector (red).
It does not matter in which order you add the vectors. Regardless of how these vectors are added together, the red resultant vector will always be the same.
To calculate the resultant vector’s magnitude and direction:
If you can take two vectors at right angles and make a diagonal vector,
What is the length of the resultant?
Separate the right vector into its x- and y- components.
By adding the original 8m plus the horizontal component (x) of the angled vector,
Then using the vertical component (y) of 6m, you can get the length of the
You can calculate the angle or the resultant vector by using the arc tangent of 6/18.4:
a) Velocity is speed AND direction.
Velocity also includes the angle:
The velocity is: 8.8m/s @ 25.4˚
b) tan(25.4˚) = x/40m
c) v = d/t therefore t = d/v
Examples of how river vectors are applied in the real world: