1. Where and When
Section 2-2

2. Coordinate Systems
Coordinate system – defines the location of the zero point and the direction in which the values increase
Origin – the point at which both variables have the value zero
Position – the separation between the object and the origin
You can have an object with a negative position
Distance – how far an object is from the origin

3. Vectors and Scalars
Vector – a quantity that has both magnitude and direction
Magnitude – size
Vectors can be represented by arrows
Ex: Velocity and Acceleration
Scalar – a quantity that is just a magnitude without any direction
Ex: Temperature, time or distance

4. Adding Vectors
Adding vectors is similar to adding scalars or regular numbers
Ex: You walk .5 mi. east to school. After school you walked 1 mi. east to a friends house. How far from the origin are you at the end of the trip?
1.5 mi. east
Resultant – the vector that represents the sum of the other two vectors

5. Time Intervals and Displacements
Time Interval – the difference between two times
Equal to the final time minus the initial time
Δt = tf – ti
Displacement – change in position
Equal to the final position minus the initial position
Different than distance
Δd = df – di

6. Vector Subtraction
Reverse the subtracted vector and add it to the other
This can be done because:
A – B = A + (-B)
Ex: You drive 5 mi. North to Sheetz. You then drive 2 mi. south to your grandmother’s house. How far are you from the origin?
3 mi. North

7. Tip to Tail
When adding vectors using graphs, place the tip of the second vector to the tail of the first vector.
The resultant is then the vector that connects the tip of the first vector to the tail of the second