University of Virginia
Physics Department

## Human Motion

A Physical Science Activity

2003 Virginia SOLs

• PS.1
• PS.10

Objectives

Students will

• learn to graph one-dimensional motion: position vs. time;
• learn the relationship between position and velocity;
• learn to use TI-83 graphing calculators, CBL system, and motion detector probe;
• understand how to use the graphing calculator system to analyze motion.

Motivation for Learning

Materials List:

• TI-83 graphing calculator. A TI-83 plus is even better, and the TI-82 can be used with different but appropriate software
• CBL system
• Vernier motion detector (or CBR)
• Meter stick
• TI View Screen for transparency projector or TI Presenter for TV
• Transparency projector or TV

In this simple use of the motion detector we want the students to become familiar with the use of the TI-83 graphing calculator, CBL system, and sonic motion detector by doing a simple match with the motion experiment in front of the class. Go through all the procedures of setting up the motion detector. First, place the motion detector about mid-chest high facing an area about 4-6 m in length that is fairly free of obstructions like tables and chairs. Using the meter stick and masking tape, mark off the following intervals (in meters) from the front of the motion detector: 0.5, 1.0, 2.0, 3.0, 4.0.

You will want to use the Texas Instrument View Screen device for a transparency projector or the new TI Presenter to be used with a TV. This will allow students to see what is on the screen of the graphing calculator as you do this experiment. You will need to use the special graphing calculator that comes with this system. This calculator has a special connection that allows the screen to be observed externally. Follow the directions of whichever viewing device you use to display the graphing calculator screen. Link the graphing calculator and CBL with link cable provided. Make sure the cable is firmly pushed in. Connect the motion detector to the special Sonic input of the CBL. If you are using the new Texas Instrument Calculator Based Ranger (CBR) motion detector, you will not need to use the CBL. Follow the directions given with the CBR, which are simpler than those given here.

Have the program PHYSCI loaded into your TI-83 (or TI-83 plus) calculator.

• Push the key PRGM on the calculator.
• Choose the program PHYSCI on the screen and press ENTER.
• Keep pushing ENTER until you see the MAIN MENU.
• Select SET UP PROBES from the menu and enter 1 for the number of probes.
• Press ENTER. We will stop stating press ENTER, because it should be clear when to do this.
• From the SELECT PROBE menu, choose MOTION (you will have to go through MORE PROBES to reach this).
• Choose MATCH from the MAIN MENU that is shown.
• Choose DISTANCE and read the directions on the screen

Ask the students to each make a prediction of what they think the result should be when you correctly perform the experiment. The calculator screen will display distance (in meters) vs. time (in seconds). It is important for students to make their own prediction. Then ask them to turn to their neighbors or group and briefly discuss with each other. After a couple of minutes ask the class to state their group's prediction. Draw on the board a couple of the predictions. NOW DO THE EXPERIMENT. Data will be collected for 5 s. It is a good idea to let a student be the human in front of the detector. You will have to push ENTER twice to take data. Mention the correct and incorrect predictions and why they were right or wrong. The predictions may or may not be taken up, but never graded! We never want to penalize the students for making predictions; we want them to learn, and research has shown this to be an effective way.

You may want to continue with the same match or try a new match. Press ENTER after examining the data and there is a menu from which you may choose SAME MATCH or NEW MATCH. Try the NEW MATCH and let a different student try it each time. The motion to match will be shown on the screen. Let the students see the graph and think about where they want to start and how they want to move to match the new graph. This can be lots of fun!
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Background Information

There are many good references for these activities. Both Vernier Software and Texas Instruments sell books and manuals for use with graphing calculators. If you do not already have CBLs and motion detectors, the single best investment you could make would be to purchase several Calculator Based Rangers (CBRs) from Texas Instruments. They can be purchased through Tech Line in Virginia (http://www.tech-line-inc.com/) at 800-777-3635. The TI-83 plus is an excellent graphing calculator and there is much support for it available.

References:

1. Physical Science with CBL, by Donald L. Volz and Sandy Sapatka, Vernier Software (1997). (503)297-5317; www.vernier.com
2. Physics with CBL, by John E. Gastineau, Kenneth Appel, Clarence Bakken, Richard Sorensen, David L. Verner. Vernier Software. See www.vernier.com
3. Math and Science in Motion: Activities for Middle School, by Chris Brueningsen, Elisa Brueningsen, and Bill Bower. This manual assumes use of the CBR (calculator based ranger) Texas Instruments. See www.ti.com/calc/

You have a couple of choices for the Student Activity. If you do have ample CBLs, motion detectors, and graphing calculators, it would be best to have the students work together in groups to do these activities themselves. If not, it is still worthwhile for you to continue with the set up you used for the Motivation, that is, the system set up for display of the graphing calculator screen so the students can see it. The student activity will be written as if the students are doing them in groups, but you can adapt these procedures as needed.

### Student Activity

Materials

• TI-83 graphing calculator. A TI-83 plus is even better, and the TI-82 can be used with different but appropriate software
• CBL system
• Vernier motion detector (or CBR)
• Meter stick

Procedure

PART A: DISTANCE

1. Place the motion detector about mid-chest high facing an area about 4-6 m in length that is fairly free of obstructions like tables and chairs. Using the meter stick and masking tape, mark off the following intervals (in meters) from the front of the motion detector: 0.5, 1.0, 2.0, 3.0, 4.0
2. Have the program PHYSCI loaded into your TI-83 (or TI-83 plus) calculator.
• Push the key PRGM on the calculator.
• Choose the program PHYSCI on the screen and press ENTER
• Keep pushing ENTER until you see the MAIN MENU. Select SET UP PROBES from the menu and enter 1 for the number of probes. Press ENTER. We will stop stating press ENTER, because it should be clear when to do this.
• From the SELECT PROBE menu, choose MOTION (you will have to go through MORE PROBES to reach this).
• Choose MATCH from the MAIN MENU that is shown.
• Choose DISTANCE and read the directions on the screen.
3. Follow your teacher's directions and match the motion described or shown on the screen. Try several of the NEW MATCH displays, which are quite different from each other. Take turns operating the calculator and matching the distance vs. time motion in front of the motion detector. When finished, choose QUIT from the OPTIONS menu.

PART B: VELOCITY

Set up the PHYSCI program as before. When in the MATCH menu, choose VELOCITY and follow the directions on the screen. You can again decide to use the SAME MATCH or try a NEW MATCH. In the display, each tick on the velocity scale is 0.25 m/s, and data will be collected for 5 s.

• Try to match the motion shown on the screen. Carefully choose your starting position to allow you to obtain the motion shown. Discuss with your partners before you move what motion you should do.
• After attempting to match the graph shown, critique the result with your partners. Discuss how it could be improved and repeat the SAME MATCH if desired.
• Have each partner try a brand NEW MATCH.
• Continue until finished and when you are done, choose QUIT from the OPTIONS menu. Choose EXIT from the MAIN MENU to exit the program.

Extensions

1. Have students make up their own motion graphs to have their group members try to match with the motion detector.
2. Have the students make up written instructions for motion and have their group members draw graphs for both position and velocity.

Students with Special Needs

Some students will need help with operating the calculator and in understanding the motion graphs.

Click here for further information on laboratories with students with special needs.

Assessment

1. Describe in your own words on the right what motion you must do to match the graph shown.

2. Describe in your own words on the right what motion you must do to match the graph shown.

3. Describe in your own words on the right what motion you must do to match the graph shown.

4. Describe in your own words on the right what motion you must do to match the graph shown.

5. Sketch the motion for a bicycle starting from rest, moving down the street, stopping for a second, and then continuing in the same direction.

6. Describe in your own words on the right what motion you must do to match the graph shown.

7. Describe in your own words on the right what motion you must do to match the graph shown.

8. Describe in your own words on the right what motion you must do to match the graph shown.

9. Describe in your own words on the right what motion you must do to match the graph shown.

10. Sketch the velocity for a bicycle starting from rest, increasing its speed gradually for 10 s while moving down the street, moving at this speed for 10 s, and then suddenly stopping in 3 s.