Graphing Speed Making and Interpreting Making and Interpreting Distance – Time Graphs Distance – Time Graphs
Dec 13, 2015
Graphing Speed
Making and InterpretingMaking and Interpreting
Distance – Time GraphsDistance – Time Graphs
GRAPHING SPEEDDISTANCE-TIME GRAPHS
DISTANCE
TIME
Distance is plotted onthe vertical axis.
Time is plotted on the horizontal axis.
CONSTANT SPEED
So…what does the term constant speed mean?
If something is “constant” what does that mean?
It does not change
Speed that does not change is constant speed.
GRAPHING CONSTANT SPEEDDISTANCE-TIME GRAPHS
DISTANCE(m)
TIME (sec)
0 1 2 3 4 5
100
90
80
70
60
50
40
30
20
10
t d
1
2
3
4
5
20
40
60
80
100
Describe the shape of the line for constant speed
straightdiagonalline
GRAPHING CONSTANT SPEEDDISTANCE-TIME GRAPHS
DISTANCE(m)
TIME (sec)
0 1 2 3 4 5
100
90
80
70
60
50
40
30
20
10
t d
1
2
3
4
5
20
40
60
80
100
Which object has the greatest constant speed?
A
B
C
A has the >slope thereforeit has the >constant speed.How do you know?
GRAPHING AVERAGE SPEEDDISTANCE-TIME GRAPHS
DISTANCE(m)
TIME (sec)
0 1 2 3 4 5
100
90
80
70
60
50
40
30
20
10
t d
1
2
3
4
5
10
30
40
40
80
Describe the shape of the line for average speed?
zigzag
What does this part of the linemean?
A flat horizontalline meansmotion stopped.
Average SpeedAverage speed is speed that changes or fluctuates.
Most moving objects travel at average speed,they start from a stand still, begin slowly, increase their speed, slow down, speed up, and eventually slow to a stop.
On a distance-time graph average speed wouldappear as a line that changes direction as it goes across the graph. It would be described asa zig-zag line.
A slanted line indicates that motion is occurring.A flat horizontal line indicates that motion hasstopped but time continues.
You will recall from a previous lesson thatSpeed is calculated using the formula
s = d / tWhat is the average speed of a 18 wheelerdriver who drives non-stop 1600 miles from Houston to Los Angeles in 23 hours?
S = d / t
S = 1600 mi / 23 hrs.
S = 69.565 m/hr.
Review
AccelerationIn order to understand acceleration you mustunderstand the difference in speed and velocity.
Speed is how long it takes a moving object to travel a distance.
Velocity is speed in a given direction.
NOW, ACCELERATION IS THE RATE OF CHANGEIN VELOCITY.
You must understand that if either speed ordirection changes, the object has undergoneacceleration.
In this diagram, how many times will the people experience acceleration from where they are now to the end of the ride?
12
Is there anyother place that its velocity willchange?
Speeds up
Speeds up???
Slowing downis also consideredto be acceleration.
I count 6 …. Let’s look at why this might be.
Changes direction?
3
4
5
6
Formula for CALCULATING ACCELERATION
acc =
final velocity - original velocitytime for change to occur
acc =Vf - Vo
tAt the top of the hill the roller coaster is moving 20 m/secand increases in speed to 40 m/sec at the bottom of thehill. It takes 4 seconds to reach the bottom of the hill.What is the roller’s coaster’s acceleration?
acc = Vf_-_Vo
t
acc =40 m/s__-__20 m/s
4 sec
acc = 5 m/s/s
As it goes up the hill, it slows to 20 m/sec.The total time from the bottom of the hill to the top of the next hill is 5 seconds. What isthe acceleration of the roller coaster?
acc =
Vf__- Vo
t
acc =20 m/s_-_40 m/s
5 seconds
acc = - 4 m/s/sNotice that the answeris a negative number.This indicates that the roller coaster slows down.
Negative acceleration is also known as__________________.deceleration
GRAPHING ACCELERTIONDISTANCE-TIME GRAPHS
DISTANCE(m)
TIME (sec)
0 1 2 3 4 5
100
90
80
70
60
50
40
30
20
10
t d
1
2
3
4
5
10
20
40
70
110
Describe the shape of a line showing acceleration.
Graphing is something that you must learn
how to do in order to be able to pass TAKS !
Let’s check out the First Annual SHMS
Snail Race results to see if you can interpret a distance time graph.
INTERPRETINGDISTANCE-TIME GRAPHS
DISTANCE(in)
TIME (hr)
0 1 2 3 4 5
100
90
80
70
60
50
40
30
20
10
a
b
c
d
Pass out questionsheet for this slide.
(sec)(sec) AA BB CC DD
00 00 00 00 00
11 33 22 44 .25.25
22 66 44 88 .5.5
33 99 66 1212 11
44 1212 88 1616 33
55 1515 1010 1616 66
66 1818 1212 1616 1010
77 2121 1414 1616 1515
88 2424 1616 1919 2121
99 2727 1818 2222 2828
1010 3030 2020 2525 3636
Time Total distance covered (meters)
Construct adistance –time graphfor the valuesin the datatable.
PASS OUT GRAPHPAPER FOR THISEXERCISE.
NEATNESSCOUNTS !
0
5
10
15
20
25
30
35
40
0 1 2 3 4 5 6 7 8 9 10
A B C D
D I S T A N C E(m)
TIME (sec)
Your graph should look similar to this.
We hope that you have been able to learn something from us.TheEnd