This document discusses key concepts in one-dimensional motion physics including displacement, distance, velocity, speed, and average velocity. It provides examples and problems to illustrate the differences between scalar and vector quantities as well as distance and displacement. Graphs are used to represent motion data and calculate instantaneous and average velocities from slopes of the position-time graphs at different time intervals. Students are prompted to practice examples, self-assess their understanding, and complete a lab assignment.

1. Physics
Displacement and Velocity
08/25/2012

2. Learning Modules
O We will be using learning modules and
other activities to gain the knowledge
necessary to master physics.
O Please have your notebook and textbook
available to complete requested tasks.

3. Focus Topics
O How is displacement different from distance?
O What is One-Dimensional Motion?
O Identify the difference between scalar and
vector quantities.
O How is velocity different from speed?
O What is Average Velocity and how is it
calculated?
O How to represent and interpret velocity
graphically? Identification of Instantaneous
Velocity.

4. Continuous Assignment
O Throughout this chapter keep a journal (in
your folder) that collects each formula
discussed.
Example:
Displacement: Δx= xf - xi
Displacement= change in
position=
final position-initial position

5. Scalar Quantities
O Scalar is quantities (amounts) that are
fully described by a magnitude (or
numerical value) alone.
Magnitude= The size of an object; no
direction
A has a greater magnitude than B

6. Examples of Scalar
O 68 degrees Fahrenheit
O $37.50
O 35 mph
O 7000 ft
Graphical representations will be discussed
later.

7. Vector Quantities
O A Vector is something that has two and
only two defining characteristics:
1. Magnitude : the meaning of magnitude
is 'size' or 'quantity‘
2. Direction: the meaning of direction is
quite self-explanatory. It simply means
that the vector is directed from one place
to another.

8. Examples of Vector
O 35 mph EAST
O 7000 feet NORTH
O 20 miles NORTHEAST
Graphical representations of these will be
discussed later.

9. Self-Assessment
O In your notebook, come up with 4 example
each of scalar and vector quantities.
4 vector examples
4 scalar examples

10. ActivWords
For the blanks on the left side. Place a √ by the
word you know and a X by the word you do not
know.
__ One Dimensional Motion __
__ Distance __
__ Displacement __
__ Velocity __
__ Speed __
__ Slope __
__ Instantaneous Velocity___

11. One Dimensional Motion

12. Another Example

13. Distance
O Distance is the magnitude between two
interval points. (Scalar Quantity)
Distance= Sum of total movement
Chris walked 200 yards to Cherry’s house. He
left Cherry’s house and walked 50 yards to the
store. After leaving the store he walked to same
path home.
What was the total distance traveled by Chris?

14. Displacement
Displacement= the change in position of an
object. (Vector Quantity)
Δx = xf – xi
Chris walked 200 yards to Cherry’s house. He
left Cherry’s house and walked 50 yards to the
store. After leaving the store he walked to same
path home.
What was Chris’ total displacement?

16. Prompt
O Explain the difference between distance
and displacement. Provide Examples
O Explain the difference between scalar and
vector. Provide Examples.
Answer in complete sentences.

17. Complete this problem.
Steven wakes up every morning to run. He
runs up the street 12 blocks (north). He
turns around runs 8 blocks (south) to a local
store to pick up his morning sausage and
biscuit. While he eats, calculate his
displacement and distance up to the store.
*Remember which one is scalar and which
one is vector.

18. Positive and Negative
Displacement

19. Positive Displacement

20. Negative Displacement

21. Wait I thought displacement
was a vector quantity!
Correct. Although a sign is sufficient when
directions are not given.
For example: -4 meters is a vector
representation

22. Example
Is this positive or negative
displacement?

23. Prompt
O Explain the circumstances surrounding a
positive or negative displacement.

24. Research
O Look up the difference between speed
and velocity?

25. Speed
O Speed is the amount of distance covered
over a certain period of time. (Scalar)
Speed = distance
time

26. Velocity
O Velocity is the rate at which an object changes
(displacement) position over a period of time.
(Vector)
Velocity= displacement or
time
Average Velocity = Δx = xf-xi
Δt tf-ti

27. Example
Velocity= 2 ft/sec east

28. Let’s look at an example
problem
Trey runs the 400 m race in 49.45 seconds.
What was his average velocity?
Vavg = ΔDisplacement
ΔTime
(400-0) = +8.1 m/s
(49.45-0)

29. Let’s look at another example
O Laquisha’s average velocity as she drove
to the store was 12 miles per hour (Lots of
traffic). It took her 20 minutes to reach the
store. How much distance did she travel.
20 min. X 1 hour = 20/60= 0.33 hours
60 min.
12 mph= Displacement = 3.96 miles
0.33 hours

30. Page 44
O Complete problems on page 44: Practice
2A

31. Prompt
O Explain the difference between speed and
velocity. Provide examples
O I did not provide a definition for average
velocity. Just by examining the formula,
provide a good definition.

32. ActivGrouping
O What are three words that come to mind
when you think of slope.
Write this in your notebook and email them
to me.
tsande13@gmail.com

33. O Create a line graph to represent the data
given.
Time (x) Position (y)
0 0
1 3
2 6
3 9
4 4
5 7
6 10

34. What can this graph tell us?

35. Chart Exercise
O Using the chart complete the following:
Example: What is the slope between 0-3
seconds?
Slope= yf-yi = 9-0 = 9/3 or 3
xf-xi 3-0
2) 2-4 seconds
3) 3-6
4) 0-6

36. Guess what?
O You have actually found multiple average
velocities.
O So, for your example the average velocity
was +3 m/s

37. What else can this
graph tell us?

38. Chart exercise
This time find slope at individual points.
Example: 3 seconds
Slope= y/x 9/3 or 3 m/s
1) 2
2) 4
3) 5
4) 0

39. Instantaneous Velocity
O You just calculated instantaneous velocity.
The example given illustrates that at 3
seconds the instant velocity was +3 m/s
What is going on between 3 & 4?
What would it mean if the line between two
time periods looked liked this “ “

40. Section wrap-up
O Go back to slide 10 and complete right
side of the assessment now that we have
worked with the terms.
O Complete lab (see materials in
blackboard) at home or in class
O Graphing Assessment