1) Physics quantities can be scalars or vectors. Scalars have magnitude only, like distance or speed. Vectors have both magnitude and direction, like displacement. 2) Displacement is the vector between the starting and ending points of an object's motion. It can be less than the total distance traveled if the object does not move in a straight line. 3) Vectors are represented by arrows, with length for magnitude and angle for direction. Vector addition uses the parallelogram method or tip-to-tail method to find the resultant, or sum, vector.

2. All physics quantities fall into one of two
categories:
Scalar – a quantity that can be described with a
single number (size, magnitude).
Ex. I drove 15 miles.
This is the quantity known as distance

3. Vector – a quantity that includes a number and a
direction.
Ex – I drove 10 miles south.
This quantity is known as displacement
Displacement can be defined two ways
1) distance traveled in a particular direction
2) final location relative to a starting point

4. Which person traveled the greatest distance?
Which person had the greatest displacement?

5. Vectors are represented by an arrow
- the length represents the size or magnitude
- the angle represents the direction

7. Vector Addition
Resultant: the term given for the final sum vector when
adding 2 or more vectors together
Question: 4 cm + 5 cm = ?
WRONG!!!
4 cm north + 5 cm north = ?
9 cm north
4 cm north + 5 cm south = ?
1 cm south

8. I walk 3 blocks south, 4 blocks east and
3 blocks north.
a)What is my distance covered?
b)What is my displacement?

9. How does the displacement of a moving object
compare to its distance covered?
Displacement <= distance

10. A duck walks 60 m north and then 40 m
east. Using a scale of 1 cm = 10 m, draw
the displacement vectors of the duck.
What is the resultant displacement?
What is the angle between the resultant
and north?

11. Adding vectors – the parallelogram method
also called the Tip to Tail Method

12. Add two vectors:
100 mi east
50 mi at 45o north of east
Find the length and direction of the
resultant using a ruler and protractor.

13. Resultant = 145 +/- 5
Direction = 15o

14. A = 80 mi west
B = 60 mi at 45o south of east
A+B=?
Find the length and direction of the
resultant using a ruler and protractor.

16. Using the scaled vector process, find the
magnitude and direction of the
following resultants:
1)50 m N + 30 m E + 40 m N
2) 5 m E + 5 m northwest + 10 m S

17. Speed – a measure of how fast something moves
- the rate at which distance is covered

18. Speed – a measure of how fast something moves
- the rate at which distance is covered

19. You drive 180 miles in 3 hours. What is your
average speed?

20. Average speed = 60 mile/hour
Unit for speed in SI system is
meters/second
Convert this speed to meters/second
1 mile = 1609 m
1 hour = 3600 s

21. Instantaneous speed
- speedometer
Is speed a scalar or vector?
Scalar
Velocity
- speed with a direction
- vector

22. A baseball is thrown at 90 mi/hr. How long
does it take to travel the 60.5 ft from the
pitcher’s mound to home plate? (3.3 ft = 1 m)
v = 40 m/s
d = 18.3 m
t = 0.46 s
Impossible!!!

23. A horn is sounded and the echo
returns in 4 s. How far away is
the wall?

24. Thrust SSC
763 miles per hour

26. Car 1 goes from 0 to 60 mph in 7 seconds
Car 2 goes from 0 to 60 mph in 3 seconds
Which car is faster?
Acceleration
- the rate of change of velocity
=?

27. = v f - vi v f – final velocity
vi - initial velocity
Car 2
vi = 0
vf = 27 m/s
The SI unit for
t=3s
acceleration is m/s2

28. Constant speed or velocity
“cruise control”
a=0
An airplane slows from 200 m/s to 50
m/s in 12 seconds. What is its
acceleration?

29. An airplane accelerates from a standing
start at 2.5 m/s2. After 7 s,
a)How fast is it moving?
b)How far has it travelled?