To begin with, eiher power up reboot the computer by hitting Ctrl-Alt-Delete (all at the same time). If the computer is running Windows, you can exit by typing Alt-F4. Then at the C:\> prompt type the boldface commands below:
C:\>cd \sonic
C:\SONIC>sr
this will load the Sonic Ranger software. Make sure that the Sonic Ranger module is plugged in, and then begin by trying this simple experiment. Prepare the software to take data by selecting Collect Data from the Main Menu. Next choose One Target and then hit the space-bar to skip past the screen with a beep. An empty graph should now appear, and the computer is ready to take data. Stand about six or eight feet away from the Sonic Ranger and have your lab partner point it toward you. When your partner presses a key to begin taking data, start moving slowly toward the Sonic Ranger. Do you think that you can move with a constant velocity? Try and see if you are able to. Are you able to tell from the graph of your position vs. time whether or not you have been reasonably successful? You may have to try a few times: to re-take data, simply hit Return after you are done and follow the instructions.
From this data, the software is able to construct a graph of velocity vs. time by calculating the average velocity between each of the measurements (the change in distance divided by the time interval). Since the measurements are taken very close together, the calculated velocity for each interval is reasonably close to the instantaneous velocity at any instant within that interval, as long as the rate of change of the velocity is small. To see a graph of velocity as a function of time, you must return to the Main Menu. Hit Return when you have finished taking data (hitting escape will erase your data, so make sure you hit Return) and press `N' to skip re-taking data. From the Main Menu, select Analyse Data and after that select View Graphs. This presents you with a menu of various options and settings. You can switch from one option to another by pressing the up- and down-arrow keys; you can change the setting of a given option by pressing the left- and right-arrow keys. For now, simply change the Number of Graphs from 1 to 2 by pressing the right-arrow key. Press `V' to view the graphs and hit the space-bar again to pass the beeping screen. You should now be presented with both a displacement graph and a velocity graph. How constant was your velocity?
Collect some more data (press Return to leave the graphs and go back to the Main Menu ) and try making a more complicated motion. From the displacement graph, draw a prediction of the velocity graph and then go back to Analyse Data to see whether you are, roughly, correct.