Name: ____________________________ Date: ________________ Period: ________
Purpose:
To see how position and velocity graphs correspond to real motion.
PreLab:
The motion detector that you will be using in the lab works by sending out a sound wave. The sound wave bounces off of you and then goes back to the detector. The detector measures the time it takes for the sound wave to do this and then calculates your position from that. The computer will make this calculation for you, but let’s try it out once so we see what’s going on… walk back and forth in front of
Motion Detector sound wave
The speed of sound is 343 meters/second. If it takes 0.01 seconds for a sound wave to travel from the detector to you and then back to the detector, how long is the wave in the air?
In that case, how far away are you from the detector?
1 ICP

Name: ____________________________ Date: ________________ Period: ________
1. Hypothesis A: Make a sketch predicting what your graph should look like if you move away from the detector at a constant velocity. me
2. Connect the Go!Motion Detector to a USB port on your computer, then find Logger
Pro in the applications folder and start that program. While the computer is starting up…(see #2)
3. Place (and clamp) the Motion Detector so that it points toward an open space at least 4 m long. Use short strips of masking tape on the floor to mark the 1 m, 2 m, 3 m, and 4 m distances from the Motion Detector.
4. Go to “File” and then “Open”. Open the Physics with Vernier folder. Then open the experiment file 01a Graph Matching.cmbl
. One graph will appear on the screen. If necessary, adjust the vertical axis to have distance scaled from 0 to 5 meters and the horizontal axis to have time from 0 to 10 seconds.
5. Using Logger Pro, produce a graph of your motion when you walk away from the detector with constant velocity. To do this, stand about 1 m from the Motion
Detector and have your lab partner click the green button. Walk slowly away from the Motion Detector when you hear it begin to click. Do this as many times as needed, until your group has a graph with no breaks (“anomalies”).
6. ONCE YOU HAVE A GOOD GRAPH, GET THE
INSTRUCTOR’S INITIALS: ____
7. Make a sketch of your graph here. Also, explain any differences between this graph and your prediction me
2 ICP

Name: ____________________________ Date: ________________ Period: ________
8. Hypothesis B: Using complete sentences , predict how your graph will look different when you move away from the detector at a faster velocity
9. Test your hypothesis on Logger Pro. ONCE YOU HAVE A GOOD GRAPH, GET
THE INSTRUCTOR’S INITIALS: ____
10. Was your hypothesis correct? Explain.
11. Look at the distance vs . time graph shown here.
12. Hypothesis A: Predict ( in detail and in complete sentences ) how you will walk to produce this target graph.
3 ICP

Name: ____________________________ Date: ________________ Period: ________
13. To test your prediction, open experiment file 01b Graph Matching.cmbl. Then, choose a starting position and stand at that point. Start data collection by clicking
. When you hear the Motion Detector begin to click, walk in such a way that the graph of your motion matches the target graph on the computer screen.
14. If you were not very close, discuss with your group how to modify your movements .
Repeat until your graph closely matches the graph on the screen. ONCE YOU
HAVE A GOOD GRAPH, GET THE INSTRUCTOR’S INITIALS: ____
15. If you walked at all differently than your hypothesis (#12), describe your walk:
16. Look at the distance vs . time graph shown here.
17. Hypothesis B: Predict ( in detail and in complete sentences ) how you will walk to produce this target graph.
18. To test your prediction, open experiment file 01c Graph Matching.cmbl. Then, choose a starting position and stand at that point. Start data collection by clicking
. When you hear the Motion Detector begin to click, walk in such a way that the graph of your motion matches the target graph on the computer screen.
4 ICP

Name: ____________________________ Date: ________________ Period: ________
19. If you were not very close, discuss with your group how to modify your movements .
Repeat until your graph closely matches the graph on the screen. ONCE YOU
HAVE A GOOD GRAPH, GET THE INSTRUCTOR’S INITIALS: ____
20. If you walked at all differently than your hypothesis (#17), describe your walk:
Answer the following questions briefly (one or two words).
What does it mean when a distance graph has positive slope?
What does it mean when a distance graph has negative slope?
What type of motion is occurring when the slope of the distance graph is zero?
What type of motion is occurring when the slope of a distance graph is constant?
5 ICP

Name: ____________________________ Date: ________________ Period: ________
21. Look at the velocity vs . time graph shown here.
22. Hypothesis A: Predict ( in detail and in complete sentences ) how you will walk to produce this target graph. Remember, this isn’t a position graph!
23. To test your prediction, open experiment file 01d Graph Matching.cmbl. Then, choose a starting position and stand at that point. Start data collection by clicking
. When you hear the Motion Detector begin to click, walk in such a way that the graph of your motion matches the target graph on the computer screen.
24. If you were not very close, discuss with your group how to modify your movements .
Repeat until your graph closely matches the graph on the screen. ONCE YOU
HAVE A GOOD GRAPH, GET THE INSTRUCTOR’S INITIALS: ____
25. If you walked at all differently than your hypothesis (#22), describe your walk:
6 ICP

Name: ____________________________ Date: ________________ Period: ________
26. Look at the velocity vs . time graph shown here.
27. Hypothesis B: Predict ( in detail and in complete sentences ) how you will walk to produce this target graph.
28. To test your prediction, open experiment file 01e Graph Matching.cmbl. Then, choose a starting position and stand at that point. Start data collection by clicking
. When you hear the Motion Detector begin to click, walk in such a way that the graph of your motion matches the target graph on the computer screen.
29. If you were not very close, discuss with your group how to modify your movements .
Repeat until your graph closely matches the graph on the screen. ONCE YOU
HA VE A GOOD GRAPH, GET THE INSTRUCTOR’S INITIALS: ____
30. If you walked at all differently than your hypothesis (#27), describe your walk:
7 ICP

Name: ____________________________ Date: ________________ Period: ________
31. Hypothesis C: Based on your Step 33 graph, predict what the position vs. time graph will look like.
Draw a sketch me
32. After you have sketched your prediction, switch to a distance vs . time graph on
Logger Pro to check your answer. Do this by clicking on the y-axis label and unchecking “Velocity”; then check “Distance”. Click
to see the distance graph.
Comment on how correct your prediction (#31) was. In complete sentences
What type of motion is occurring when the slope of a velocity vs. time graph is zero?
What type of motion is occurring when the slope of a velocity vs. time graph is not zero?
Consider both positive and negative slopes. Test your answer using the Motion
Detector
8 ICP