1. Speed Graphs
Objectives: SWBAT
1. Recognize distance vs. time graphs;
2. Know that distance vs. time graphs
shows the speed;
3. Read and interpret graphs.
Standards 1f: Students know how to interpret
graphs of position vs. time for motion in
single direction.
3. 1. Describing the Distance vs. Time Graph:
Y-axis
X-axis
Distance is on the Y-axis!
Time is on the X-axis!
D vs T Graph
4. Slope of a Distance vs. Time Graph
2. What does the
slope show?
Slope of a
distance vs. time
graph gives the
SPEED of the
object.
5. How the graph
looks like…
What the graph is telling
about the motion…
Draw here the
graph…
you will need
your ruler!
Write here what
the graph means…
6. Graph 1: Example of D vs T Graph:
Horizontal Line
How the graph looks
like…
What the graph is telling
about the motion…
Time at x-axis
Distanceaty-
axis
The object is at
rest.
(graph is a straight
horizontal line)
Note that the
time is
increasing to
the right, but its
distance does
7. What are examples of this motion?
The object is at
rest.
Parked cars…
Persons waiting
in line and the
line is not
moving…
8. Graph 2: Example of D vs T Graph:
Straight Line
How the graph looks
like…
What the graph is telling
about the motion…
Time at x-axis
Distanceaty-
axis
The object has
CONSTANT speed.
(straight lines represent
constant speed)
Note that the time is
increasing to the
right, but distance is
increases with the
same amount every
equal amount of
time.
9. What are examples of this motion?
The object traveling
at constant speed.
Cars on the freeway
maintaining 60 or 80
mph.
10. Graph 2: Example of D vs T Graph:
Steeper Straight Line
How the graph looks
like…
What the graph is telling
about the motion…
Time at x-axis
Distanceaty-
axis
The object with RED
line has CONSTANT
speed but speed is
faster than the object
with BLUE line.
(straight lines represent constant
speed)
Note that the RED line took
shorter amount of time to
cover the same distance, so it is
faster.
11. What are examples of this motion?
Objects that cover the
same distance with
different amounts of
time.
Car Racing!
12. Graph 3: Example of D vs T Graph:
Curve Upwards
How the graph looks
like…
What the graph is telling
about the motion…
The object increases its
speed (speeding up or
accelerating)
Note that it covers
more and more
distance for every
equal amount of
time.
Time at x-axis
Distanceaty-
axis
13. What are examples of this motion?
Objects that are speeding
up or accelerating.
Start of a
run…
14. Graph 4: Example of D vs T Graph:
Curve Downwards
How the graph looks
like…
What the graph is telling
about the motion…
The object decreases its
speed (slowing down).
Note that it covers
less and less distance
for every equal
amount of time.Time at x-axis
Distanceaty-
axis
15. What are examples of this motion?
Objects that slowing
down.
A car that is approaching
a stop (red) light is slowing
down…
16. Fifth Example of D vs T Graph:
Sloping Downward to the X-axis
How the graph looks
like…
What the graph is telling
about the motion…
Time at x-axis
Distanceaty-
axis
Both graphs show that
the object is going back
to its starting point.
Note that both
started at distance
zero and ended at
distance zero.
17. What are examples of this motion?
Objects that return to
their starting point.
You! You go to school everyday
but at night, you go back home!
(You are going back to your
starting point!)
18. Summary
1. A means the object is not changing
its position - it is or .
2. A graph with means the object is
traveling at .
3. The the line of the graph, it
means that the object’s speed is .
4. A graph with of D vs T means the
object is changing its speed, either the object is
or .
5. A graph that has
means the object is going back .
19. Summary
1. A horizontal line means the object is not
changing its position - it is not moving, it is at
rest.
2. A straight line means the object is traveling at
constant speed.
3. The steeper the line of the graph, means the
faster is the speed of the object.
4. A curved graph of D vs T means the object is
changing its speed, either the object is speeding
up or slowing down.
5. A graph line going back to zero distance means
the object is going back to its starting point.
20. Practice
The following are the descriptions
that we can use to describe the
motion of an object (say, a car):
a. The car is traveling at a constant
speed.
b. The car is stopped.
c. The speed of the car is increasing.
d. The speed of the car is decreasing.
e. The car is going back to its starting
point.
21. Graph No. 1: Let’s use what we have learned!
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
22. Graph No. 2: Let’s use what we have learned!
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
E
23. Graph No. 3: Let’s use what we have learned!
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
E
24. Graph No. 4: Let’s use what we have learned!
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
26. Graph No. 5: Find the average speed from Point A
to D:
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
10 m
20 m
30 m
40 m
2 s 4 s 6 s 8 s 10 s
50 m
27. Graph No. 5: Find the average speed from Point A
to D:
TIME (X-axis)
DISTANCE(Y-axis)
A
B
D
C
40 m
80 m
120 m
160 m
10 s 20 s 30 s 40 s 60 s
200 m
E
