A
vector has both
magnitude and
direction.
 A resultant is a 1
vector that acts as
the sum of 2 or
more vectors.
Vectors are usually named with capital
letters with arrows above the letter.
They are represented graphically as arrows.
The length of the arrow corresponds
to the magnitude of the vector.
The direction the arrow points
is the vector direction.
Examples include:
A = 20 m/s at 35° NE B = 120 lb at 60° SE
C = 5.8 mph/s west
Methods of Vector Addition

Graphical Method (Parallelogram) –
aligning vectors head to tail and then
drawing the resultant from the tail of the
first to the head of the last.
Graphical Vectors
Displacement is always a straightline pathway.
 Two vectors having the same direction
are parallel.
 Vectors are always placed head-to-tail.

Adding Vectors Linear

20 m
+
12 m
15 m/s
+
10 m/s
10 m/s

+
15 m/s
+
15m/s
When adding any vector, they must be of similar
type of values.
◦ you must have the same units for your quantities.
Methods of Vector Addition

2. Analytical Method – use Pythagorean
Theorem (you can only find MAGNITUDE
using the Theorem)
Examples-Pythagorean Theorem

A car is driven 125km due west, then 65
km due south. What is the magnitude
of its displacement?
Examples-continued…

A shopper walks from the door of the
mall to her car 250 m down a lane of cars,
then turns 90° to the right and walks an
additional 60 m. What is the magnitude
of the displacement of her car from the
mall door?
Your turn

An explorer walk 13 km due east then 18
km north. What is the magnitude of
her displacement?