1. Vectors
3 + 4 = ?

2. Vectors
Vector – A quantity which can be described by it’s magnitude and direction.
Scalar – A quantity which can be described by it’s magnitude only.
Magnitude – How big something is.
Hint – You can point in the direction of a vector.

3. Vectors Vectors Scalar - Time (3 min) - Temperature (32o)
Examples of Vectors and Scalars
Vectors Scalar
- Time (3 min)
- Temperature (32o)
Displacement (4 ft North) Distance and Length (4 ft)
Velocity (100 Km/hr South) Speed(100 Km/hr)
Force (gravity downward) -
Weight (Newton Downward) Mass (5 Kg)

4. An arrow is used to represent a vector.
Vectors
Drawing Vectors or “Graphing” Vectors
An arrow is used to represent a vector.
Arrowhead
represents
direction.
Length represents
magnitude.
Bad Vector:
3 m

5. Vectors Adding scalar quantities Mass: 1 kg + 1 kg = 2 kg
Time: 2 s + 4 s = 6 s
Distance: 10 m + 5 m = 15 m
Since we are not dealing with direction we simple add the quantities.

6. Vectors Adding vector quantities (Tip to Tail or Start to Finish)
Unlike scalars, vectors have a direction and we cannot add them like we do with scalar quantities.
Vector “A”
Start
Vector “B”
Vector “C”
= Resultant
Resultant = the addition of two of more vectors.
Finish

7. Why Does It Matter? How much did the person walk? 3 m
How far is the person from its initial position?
3 m
Distance = 3m + 4m = 7m
4 m
a2 + b2 = c2
Displacement = 5m 37o E of N

8. Example: Find the resultant of 4.3 m N and 8.5 m E
Procedure:
1. Choose an appropriate scale so each vector is about 5 – 10 cm
2. Draw the vectors to scale
3. Draw and measure the resultant
4. Measure the angle from start to resultant
1 cm = 1 m
8.5 m
4.3 m
26o
9.6 m
Resultant = 9.6 m, 260 E of N