Introduction to Vectors Guided Notes
Name:_______________
What is the difference between scalars and vectors?
Magnitude
Vector
Magnitude & Direction
20 m/s
Displacement
5 m, NW
Distance
10 m
Velocity
20 m/s, N
Age
15 years
Acceleration
10 m/s/s, E
Heat
1000 calories
Force
5 N, West
Scalar Example
Speed
A ___________________ is ANY quantity in physics that has ___________________________, but ______________
________________________________.
A ___________________ is ANY quantity in physics that has _____________________________ and
_______________________________.
How are velocity and speed related?
______________________________________________________________________________________________
______________________________________________________________________________________________
Example - 20 m/s = ______________
20 m/s NE = __________________
What is displacement?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
How to draw vectors
The _______________________ of the vector, drawn to scale, indicates the __________________ of the vector
quantity.
The ____________________ of a vector is the
____________________________ of rotation
which that vector makes with
_________________________or x-axis.
Example: Lady bug displacement
NOTE 1:
Displacement shows how far apart something is now ________
____________________________________________. It does
not show the path or the total distance travelled.
NOTE 2:
When drawing a vector you MUST MUST MUST ____________
_________________ or arrow on the vector to demonstrate
which _________________ it is pointing.
Quick Review
What is the difference between a scalar and a vector?
What are the parts of a vector?
Adding Vectors: Plane example 1 – Tailwind
A small plane is heading south at speed of 200 km/h. (This is what the plane is doing relative to the air around it)
The plane encounters a tailwind of 80 km/h.
Sketch the problem here!
To understand how far the plane is traveling
relative to the ground we need to add the
two vectors – the plane’s heading and the
tailwind.
We add vectors by ____________________
____________________________and
finding the __________________ (sum).
The resulting velocity relative to the ground
is 280 km/h S
Adding Vectors: Plane example 2 – Headwind
A small plane is heading south at speed of 200 km/h. (This is what the plane is doing relative to the air around it)
It’s Texas: the wind changes direction suddenly 1800. Now the plane encounters a 80 km/h headwind
How do we figure out the plane’s velocity
Sketch the problem here!
relative to the ground?
____________________________________
____________________________________
The resultant vector always goes from the
__________________________________
__________________________________
___________________________________
Adding Vectors: Plane example 3 – Crosswind
A small plane is heading south at speed of 200 km/h. (This is what the plane is doing relative to the air around it)
The plane encounters a 80 km/h crosswind going East.
Work the problem here!
Sketch the problem here!
The order in which two or more vectors are added _______________________________.
Vectors can be moved around as long as their length (magnitude) and direction are not changed.
Vectors that have the _______________________ and the __________________________ are ________________.
WE DO PROBLEMS
 Example: A man walks 54.5 meters east, then 30 meters west. Calculate his displacement relative to where he
started.
 Example: A man walks 54.5 meters east, then again 30 meters east. Calculate his displacement relative to where
he started.
 Example: A man walks 54.5 meters east, then 30 meters north. Calculate his displacement relative to where he
started.
You Do Problems
 A person walks 5m N then walks 8m S. Calculate his displacement.
 A ball is thrown 25 m/s E. A tailwind of 5 m/s E is blowing. Calculate the resulting velocity.
 A boat moves with a velocity of 15 m/s, N in a river which flows with a velocity of 8.0 m/s, west. Calculate the
boat's resultant velocity with respect to due north
 A bear, searching for food wanders 35 meters east then 20 meters north. Frustrated, he wanders another 12
meters west then 6 meters south. Calculate the bear's displacement.
Multiplying a Vector by a Scalar
Multiplying a vector by a scalar will ___________________________________________________________.
The exception: multiplying a vector by a negative number will _______________ its direction.