(this TIL is about older software, and does not apply to Logger Pro.)
Several people have asked about how they can create their own challenge files for students in MacMotion or Motion (MS-DOS Version). By challenge files, we mean files like Distance Match, Velocity Match, and Acceleration Match, which were on your original Motion program disk. The files will be have data loaded into Data B and Data A will be blank. The students are asked to move in front of the Motion Detector and try to match the pattern on the graph. There are three different ways to create these files: 1. Physically move an object to create a new graph to be matched and then move it to Data B. Make sure that there is no data in Data A, and save the experiment with a distinctive name. You are now ready to use the new challenge file. Have students open the file and click on Start. New data will then be collected on top of the Data B saved with the file. Some teachers have one student group make up a challenge for the next group. 2. Much as in method 1 move an object to create the challenge, but use Event Mode to collect data only at specific points. Here is a step-by-step description of this method:
· Start the Motion program. Make sure the Lines option of the Display menu is selected.
· Choose Event Mode from the Collect menu.
· Set up the kind of graph you want, with the proper scales.
· Click on the Start Button. In Event Mode data will be taken only when you click on the Keep button. This means it is easy to create straight-line segments that appear on the graph.
· You can see the vertical position of the point on the graph before you click on keep. By carefully adjusting the distance of the object from the Motion Detector as you watch the screen, you can create almost any graph you want. It will probably take several runs to create the graph you have in mind.
· After you have a graph as you want it, choose Data A->Data B from the Data menu.
· Make sure that there is no data in Data A, uncheck Event Mode on the Collect menu, and save the experiment with a distinctive name. 3. Create a new data file mathematically. This is somewhat more difficult. To summarize: you should load one of the existing challenge files and save Data B as text. Load the data file and carefully edit it with a spreadsheet program. Save the file as text. Here are step-by-step instructions for this method:
· Load one of the Match Experiments on the original disk. Pick the one closest to the kind of motion you want to have on your experiment. Here are the exact file name on the two different types of computers: On Macintosh computers On IBM-compatible computers Distance Match D_MATCH.MXP Velocity Match V_MATCH.MXP Constant Velocity CONVEL.MXP Constant Accel #1 CONACC1.MXP Constant Accel #2 CONACC2.MXP
· Choose Save DataB from the File menu.
· Make up a new file name. Check the Text button at the bottom of the Save dialog box.
· After the data file is saved as text, quit the ULI Motion program.
· Launch a spreadsheet program.
· Open the file you just saved. It will consist of five columns: Time, Distance, Velocity, Acceleration, and Force. You should not change the first column at all. It is regularly spaced time data.
· Edit the second column (Distance) to correspond to the motion you want to have students match. Note that you can use formulas like B1+ .05 to produce a constant velocity. Use the Fill Down feature of the spreadsheet to copy this formula down as many cells as you want to continue that motion. Just copy a number down to produce a period of no motion.
· When you have the Distance column just as you want it, put a formula in all the cells of the third column to calculate all the velocities. On a Microsoft spreadsheet, just place this formula in cell C1: (B2-B1)/(A2-A1) This calculates the velocity from the change in distance over the change in time.
· Use Fill Down to copy this formula to all the cells of the third column down to the last time and distance data. You may have to treat the last cell special.
· Put a formula in all the cells of the fourth column to calculate all the accelerations. On a Microsoft spreadsheet, just place this formula in cell D1: (C2-C1)/(A2-A1) This calculates the accelerations from the change in velocities over the change in time.
· Use Fill Down to copy this formula to all the cells of the fourth column down to the last time and distance data. You may have to treat the last cell special.
· Choose Save As from your spreadsheet’s File menu. Make sure you save the File as a tab-delimited text file. This is important. If you save the file in any other format, it will not work.
· Quit the spreadsheet program.
· Launch the ULI Motion program.
· Choose Open from the File Menu.
· Select the file you have just edited.
· Choose DataB as where the data should be loaded. If all goes well, the data will be loaded and you will see a graph.
· Adjust the type of graphs displayed and the scale of the axis as you wish.
· Choose Save Experiment from the File menu, and save the experiment. Be sure that the box Save DataB is checked in the Save Experiment Dialog box. Now, about the other situations: Using any system, the first method listed above will work. If you are using the MS-DOS Motion Software, you can create new challenge files fairly easily. This procedure is explained in the Teacher’s Guide section of the manual fairly completely. If you are using MPLI for Windows, the 1st method listed above is really the only easy way.