Experiment 3


Initiate the LoggerPro Program

1.  Open the LoggerPro program by clicking on the LoggerPro link. A blank graph with axes labeled Distance (m) vs. Time (secs) should appear on the screen.

2.  When you are ready to begin, click once on the Collect button in the lower left corner of the screen. You should hear a clicking sound from the detector and a red line should appear on your graph. While the line is being drawn, move your hand in front of and away from the detector and observe the result. Each time you click Collect the previous graph is erased and a new one is displayed.

3.  Measure a distance of 2 m from the detector and mark the spot with a piece of masking tape on the floor. To calibrate the detector, stand there and have your partner move the detector until the reading on the graph indicates 2 m. When calibration is complete and you are ready to begin taking data, go on to the next section. 4.  In the steps below, partners should alternate in performing the motions and controlling start-stop in every other Graphing activity (7 in all).

A. Position vs. Time Graphs

Graph 1:  Walking slowly and steadily away from the detector

1.  Stand about 0.5 meter from the detector, have your partner click Collect, and walk away from the detector slowly and steadily. Practice this a few times until you can generate a relatively smooth graph.

2.  Copy the graph by selecting EDIT...COPY from the LoggerPro menu bar.

3.  Open the Worksheet and fill in the header information.

4.  Paste the copied graph into the Worksheet by selecting EDIT...PASTE from the menu bar.

5.  Resize the graph to make it fit within a box encompassing cells A10...D22 on the Worksheet.

To do this, first select the graph by pointing and clicking once anywhere inside the outlined box containing the graph. "Handles" (small squares) will appear on the outline to indicate that it has been selected. Grab the lower right handle and, while holding down the shift key, move the pointer to resize the box as necessary. The entire box may be moved by clicking anywhere inside it, and dragging the outlined image to the desired location.

6.  Answer Questions 1 through 3 in cells F12:F16 on the Worksheet.

Graph 2  Walking medium fast and steadily away from the detector.

7.  Repeat the above procedure, but this time walk medium fast and steadily away from the detector.

8.  COPY and PASTE this graph into cells A27...D39 of the Worksheet.

9.  Answer Questions 4 through 6 for this graph in cells F29:F33

10.  In the space provided on the Worksheet, answer Question 7.

Graph 3:  Walking slowly and steadily toward the detector

11.  Prepare a third graph by walking slowly and steadily toward the detector. In this case, start as far as you can from the detector and still get reliable results.

12.  COPY and PASTE this graph into cells A52...D64 on the Worksheet, and answer Questions 8 through 10 in cells F54:F58.

Graph 4:  Walking medium fast and steadily toward the detector

13.  Prepare a fourth graph by walking medium fast and steadily toward the detector.

14.  COPY and PASTE this graph into cells A71...D83 on the Worksheet, and answer Questions 11 through 13 in cells F73:F77.

15.  Explain the difference between the graphs made by walking toward and away from the detector in Question 14.

B. Making Predictions

1.  Both partners should make their own prediction of the Position vs. Time graph that would result if you:

  • start at the 1-meter mark

  • walk away from the detector slowly and steadily for 4 seconds

  • stop for 4 seconds

  • walk quickly back to the detector and finish at the 1-meter mark

2.  Sketch your prediction on the blank graph provided for this section on the Worksheet. To make the sketch, click the media button (next to the zoom percentage box) and select the line drawing tool.

3.  Compare your prediction with that of your lab partner. Discuss your predictions with each other and resolve any differences.

Graph 5:  Following the Prediction.

4.  Now do the experiment. Try to move as described in B.1 above. When you are satisfied that you have the motion right, set up the motion detector and collect the data for this graph. Copy and Paste the Graph Window into cells A122...E136 of the Worksheet.

5.  Answer Question 15 in the space provided on the Worksheet.

C. Matching a Position vs. Time Graph

1.  A specific Position vs. Time graph has been duplicated for you in Section C.1 of the Worksheet. Review this graph and decide on the motions necessary to make each segment.

2.  Click on the link Distance.Match.

3.  To activate the Collect button again, under the Experiment menu, choose Connect Interface.

Graph 6:  Matching the Position vs. Time Graph.

4.  Now move so that you duplicate the graph. Try a number of times until you match the graph as closely as possible. Everyone in the group should get a turn. Note the critical times and distances in the figure before you begin.

5.  When you are satisfied with the result, COPY and PASTE the resulting graph in cells A172...E186 of the Worksheet.

6.  In the space provided on the Worksheet, answer Question 16.

D. Other Position vs. Time Graphs

1.  Remove the DISTANCE....MATCH graph from the LoggerPro screen by selecting Delete Data Set...Latest from the DATA Menu.

2.  One partner should make up his own position vs. time graph using straight lines and no curves. Sketch the graph on the blank set of axes provided for this purpose in Section D of the Worksheet.

Graph 7:  Matching the Partner's Graph.

3.  Now try to duplicate the graph through actual movement. After you are satisfied with the results, COPY and PASTE your LoggerPro result in cells A220...E234 of the Worksheet.

To change the collection time, select the Experiment tab at the top of the screen. Select Data Collection, and then Change Collection Time.

4.  Consider the three Position vs. Time graphs shown below:

In the space provided on the Worksheet, answer Question 17 describing how you must move to produce each of these graphs.

5.  When you have completed the Worksheet you can print out your results by selecting FILE....PRINT from the Menu.

6.  Print out the Worksheet and use it to develop your lab report.