Experiment 3

Experiment 3

MOTION - II

PROCEDURE

A. Making Velocity Graphs

Graph 1: Walking away from the detector

1. Open the Motion-II Workbook, and fill in the header information.

2. Activate the LoggerPro link and 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 graph with none, or just a few erratic segments.

NOTE: If you need to alter the velocity or time scales so that the plot fills nearly all of the available space, click anywhere on the graph and change the velocity and/or time ranges which appear in the dialog box.

3. When you are satisfied with your results, select Store Latest Run from the LoggerPro EXPERIMENT menu.

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

5. When you are finished, copy the graph to the clipboard by selecting EDIT....COPY from the LoggerPro menu.

6. Return to the Worksheet window and PASTE the copied graph into cells A11...G25 on the Worksheet. Do this by placing the cursor in cell A11 and selecting EDIT....PASTE from the Worksheet menu.

7. Ignoring erratic parts of your plots caused by uneven walking or detector error, answer Questions 1 through 3 on the Worksheet.

NOTE: If you need to resize the graph to make it fit within the designated cells on the Worksheet, first select the graph by clicking on it. Then, grab the lower right handle of the box and move the handle to resize the box as necessary. The box may be moved by clicking anywhere inside it and dragging the outlined image to the desired location.

Graph 2: Walking toward the detector

8. Return to the LoggerPro window, and prepare a second graph by walking slowly and steadily toward the detector. Start as far as you can from the detector and still get reliable results.

9. When you are satisfied with your graph, select Store Latest Run from the LoggerPro EXPERIMENT menu.

10. Repeat by walking medium fast and steadily toward the detector. Do not transfer these data.

11. When you are satisfied with your results, COPY and PASTE the graph into cells A47...G61 on the Worksheet. Resize as necessary (see note above).

12. Answer Question 4. Ignore erratic parts of the plot caused by uneven walking, etc.

B. Making Predictions

1. Predict the Velocity vs. Time graph that would result if you:

walk away from the detector slowly and steadily for 10 seconds

stop for 4 seconds
walk toward the detector steadily about twice as fast as before

2. Sketch your prediction on the blank graph provided in Section B of the Worksheet.

First activate the Shapes Palette by selecting Insert → Shape... from the main toolbar at the top. Then page down or select Lines and Connectors from the palette drop-down menu.

Select one of the line drawing tools from the palette by clicking the mouse on it and then draw your prediction on the graph using the mouse. (See the Note below.) When you finish, your line will appear with "handles". If acceptable, click anywhere off the line. If not, delete the line by pressing the delete key while the line is selected (handles showing), reselect the line drawing tool, and redraw the line.

NOTE: Straight-line segments can be made with the Straight Line tool: . Click at the starting point of the line and release at the ending point. (Straight lines can be made horizontal or vertical by pressing the shift key while moving the mouse.) The Curve tool, , creates a smooth curve through the points you select by clicking the mouse. (Double click to finish.) The Scribble tool, , draws a line following movements exactly while the mouse is depressed.

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

4. On the plot, extend the time scale to 20 s by clicking on the graph and setting the x-axis limit. Also under the LoggerPro EXPERIMENT menu, choose Data Collection and set the Length under the Collection Tab to 20 s.

5. Now do the experiment. Both you and your lab partner should move as described in Step 1 above. When you are satisfied that you have the motion right, set up the LoggerPro detector and collect the data for this graph. COPY and PASTE the LoggerPro graph into cells A93...G108 of the Worksheet.

6. Answer Question 5 on the Worksheet.

C. Matching a Velocity-Time Graph 1. A specific Velocity vs. Time graph has been prepared for you and stored as a file entitled Velocity.Match. Click on the Velocity.Match link to open this LoggerPro window. If the Collect button is not activated, go to the EXPERIMENT menu and select Connect Interface.

2. Now try to move so that you duplicate the Velocity.Match 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 velocities in the figure before you begin.

3. When you are satisfied, COPY and PASTE the matched graph to the Worksheet in cells A120:G135.

4. Answer Questions 6 through 10 on the Worksheet.

5. When you have completed the Worksheet, print it out by selecting PRINT under the FILE menu, and use it to complete your lab report.