Name: _______________________________________ Block: ____________ Date: _____________
Graphing Motion Lab
Conceptual Physics
Mr. White
G ra ph ing M ot ion Lab
Pre-Lab Information
Read the following excerpt and use your notes to answer the Pre-lab Questions.
Scientist can use math and graphing to describe and display the motion of an object. One method is to plot the location of an object,
known as its position, during different points in time. Depending on how the scientist measures their observations will determine the
correct graphical representation of the data.
If a scientist observes a single variable and how it continuously changes over time, then the scientist would represent this data with a
line graph. This graph represents one observed event for a continued amount of time. A scientist can also observe an object moving
many different times and observe a relationship between the change in position and the time interval of the motion. In this
experiment, the scientist would plot a scatter plot graph to represent the data. After the plotting the data, they would draw a line of
best fit to average out the values and determine an overall picture of what is happening.
In either case above, the graph the position of an object can tell scientist more than just its
location. If the scientist chooses a reference point, they can then measure the observed
objects position from that reference point. If the object is on the reference point, then the
initial position would be zero. The graph to the right is an example of a car stopped a stop
sign. The initial observation of the car at t = 0 seconds, shows the car at the same position as
the sign. After 5 seconds, the car is now in a new position 10 m from the stop sign. This graph
shows the location of the car from any time between 0 and 15 seconds. A scientist can use
this graph to calculate the velocity of the car and even tell if it is accelerating or at a constant
velocity.
Look at the example of the Position vs. Time graph again. When position is plotted on the Y-Axis and time on the X-Axis, the slope of
the line will be equal to the speed. We can make this claim by looking at the equation for slope and the equation for speed.
𝑠𝑙𝑜𝑝𝑒 =
∆𝑌
∆𝑋
𝑆𝑝𝑒𝑒𝑑 =
∆𝑑
∆𝑡
Speed is the change in distance divided by the change in time. For a Position vs. Time graph, that means taking the change in the
variable on the y-axis and dividing it by the change in the variable on the x-axis. In algebra we learned that when you do that for a
line, you have calculated its slope. So the slope of the line is equal to the speed of the object. If the object moves faster, then it has
a greater slope. If the graph is curving (the slope is changing) then the object is accelerating because its velocity is changing.
Constant Speed & Graphing 1
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Name: _______________________________________ Block: ____________ Date: _____________
Graphing Motion Lab
Mr. White
Pre-Lab Assessment – Read the Background Information First!!!
1.
What type of graph is used to display a relationship between two variables after observing multiple events?
________________________________________________________________________________________
2.
What part of a Position vs. Time graph represents the velocity of an object? ____________________________
3.
What does the y-intercept of a Position vs. Time graph represent? ____________________________________
4.
In the sketched Position vs. Time graph above, which object has a greater velocity? How can you tell?
_____________________________________________________________________________________________________
_____________________________________________________________________________________________________
5.
How will the Position vs. Time Graph of an object that is accelerating look different from one that has a constant velocity?
__________________________________________________________________________________________
__________________________________________________________________________________________
Materials per Lab Group





2 Toy vehicle (Train & Car)
One ball
1 Meter Stick
1 Dry Erase Marker
1 Stopwatch
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Graphing Motion – Conceptual Physics
Mr. White
Data Collection
Procedure
1. Measure 20 centimeters from the end of the white track. Mark this location with a straight line
across the whiteboard track.
a. This line represents a Position of 0 cm and will serve as you reference point for the
entire lab.
2. Using the meter stick, measure and mark the positons 50 cm, 100 m, 150 m and 200 m.
PART 1
3. Place the FRONT of the toy on the tape.
4. Turn on the toy, but hold it above the ground so that it does not start to move down the track.
5. When the timer says go, the toy operator will let go of the toy and allow it to move on its own
down the floor. The Timer or a second partner should use the dry erase marker to mark the
location of the front of the toy every 2 seconds until the toy has reached the end of the track or 10
seconds have gone by. If the toy does not go in a straight line, set it against the side to make sure
it goes straight!!!
6. Using the meter stick, measure the position of each dry erase mark that corresponds with the time
interval.
PART 2
7. Now place the toy at the 200 cm mark and run the toy towards the position of 0 cm.
8. Repeat Step 5 from part 1.
9. Measure the distance from the 0 cm position (your reference point) to each dry erase mark.
PART 3
10. Place the 2nd Toy at the initial position of 0 cm.
11. Repeat steps 4 through 6 in Part 1.
PART 4
12. Place three physics textbooks under the 0 cm end of the white track.
13. Hold a ball at the initial positon.
14. When ready, let the ball roll down the ramp and mark its position every 2 seconds.
15. Repeat this experiment two more times.
16. Average the position values for all three experiments for more accurate results.
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Graphing Motion – Conceptual Physics
Mr. White
Data Collection Table
PART 1 Data Collection Table
Type of Toy:
Type of Toy:
Time (s)
PART 2 Data Collection Table
Position (cm)
Time (s)
0
0
2
2
4
4
6
6
8
8
10
10
PART 3 Data Collection Table
PART 4 Data Collection Table
Type of Ball:
Type of Toy:
Time (s)
Position (cm)
Position (cm)
Time (s)
0
0
2
2
4
4
6
6
8
8
10
10
Position (cm)
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Average Position (cm)
Graphing Motion – Conceptual Physics
Mr. White
Creating Positon – Time Graphs.
1. Use the data collected and the Graph Templates Below to create Position – Time Graphs for Each part of the
experiment.
Part 1: Position - Time Graph
200
180
160
Position (cm)
140
120
100
80
60
40
20
0
0
1
2
3
4
5
6
7
8
9
10
7
8
9
10
Time (s)
Part 2: Position - Time Graph
200
180
160
Position (cm)
140
120
100
80
60
40
20
0
0
1
2
3
4
5
6
Time (s)
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Graphing Motion – Conceptual Physics
Mr. White
Part 3: Position - Time Graph
200
180
160
Position (cm)
140
120
100
80
60
40
20
0
0
1
2
3
4
5
6
7
8
9
10
Time (s)
Part 4: Position - Time Graph
200
180
160
Position (cm)
140
120
100
80
60
40
20
0
0
1
2
3
4
5
6
Time (s)
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7
8
9
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Graphing Motion – Conceptual Physics
Mr. White
Analysis of Data and Graphs
1. Based on PART 1 & PART 2 graphs.
a. How does the slope of the graph indicate the direction the toy is moving?
b. Did the toy move faster in either of the trials? Explain how you can use the graphs to justify your
answer.
c. Use your graph from PART 1 to estimate the positon of the toy at 5 seconds.
d. In the prelab you learned that the slope of a Position – Time gaph equals the average velocity of the
object. Calculate the slope for both PART 1 & PART 2 to confirm your answers to questions (a) and (b).
2. Based on PART 1 & PART 3 graphs.
a. Did the second toy move faster or slower than the first toy?
i. How can you tell based on the slope of the graphs?
b. How would the graph of PART 3 look different if it was going in the opposite direction?
3. Based on PART 4 Graph.
a. Was the slope of the line the same throughout the entire 10 seconds interval recorded?
i. What does this mean in terms of the velocity of the ball?
b. When did the ball have the greatest veloctiy?
c. Calculate the slope of the line for the final portion recorded on the graph. This represents the final
velocity of the ball.
i. If the ball started from rest, what was the acceleration of the ball as it rolled down the ramp?
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Graphing Motion – Conceptual Physics
Mr. White
Lab Reflection and Review
1. For PART 1, what was the independent variable, dependent variable and 2 constants throughout that experiment.
2. The purpose of this lab was to reinforce that the slope of a position – time graph of a moving object represents the
_______________ of an object.
3. Even though our two toys didn’t race down the track at the same time, use the graphs from PART 1 and PART 3
to determine where the slower vehicle would be when the faster on reached the 200 cm mark.
4. What is one human error that occurred during the data collection that could have messed up the results of the
experiment?
5. Why would it be important for our toys to move in a straight line when we were collecting the data?
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