1. Divide the class into two groups.
Group 1 gets the following materials: 4 bottle caps, 2 short pencils, 1 can, and half of the clay. Group 2 gets the following materials: 4 CDs, 2 long pencils, 1 water bottle, and half of the clay.
2. Slide each pencil through the holes of your bottle or can. Make sure the pencils are straight.
3. Attach either the bottle caps or the CDs to the pencils with clay. You may need to put clay on both sides of the CDs to prevent them from sliding off the pencils.
4. Make a ramp. Set up the pile of books. Place the cardboard so one side rests on the books. The other side should rest on a flat surface.
5. Place a 1-foot-long piece of masking tape on the floor. One end of the tape should touch the cardboard ramp. The tape will be used to mark the distance your car travels on the line.
6. Predict how many inches your car will travel. Write down your prediction.
7. Group 1, place your car at the top of the board. Release it. Mark where the car stops. Measure and record the distance it traveled in fractions of an inch. Repeat this three times.
8. Group 2, do steps 6 and 7.