| 1 fat rubber band | 1 board | 15 weights |
| 1 medium rubber band | 1 clamp | 2 index cards |
| 1 skinny rubber band | 2 paper clips | 1 bucket |
| 2 pieces of cellophane tape |
2. Clamp the board to the desk. Hang one hook (made from a paper clip) from the ring on the board. See Figure 1.
3. Tape 2 index cards together as shown in Figure 2. Fold them at one end and tape the folded part to the top of the board. See Figure 3.
4. Hang the skinny rubber band from the hook. Use the second hook (paper clip) to hang the bucket from the rubber band. See Figure 4.
5. Add weights gently until the bottom of the rubber band is even with the bottom of the index cards. Write down how many weights you use in the chart below.
6. Now hang the fat rubber band from the hook. Hang the bucket on the fat rubber band. How many weights does it take to stretch the fat rubber band to the bottom of the index cards? Record your answer below.
7. Now think! Based on what you have seen already how many weights do you think it will take to stretch the medium rubber band? Write your prediction below.
| TYPE OF RUBBER BAND | PREDICTION | WEIGHTS NEEDED |
|---|---|---|
| Skinny |  |
|
| Medium | |
|
| Fat | |
|
8. Do the experiment to find out how many weights are needed. Record your answer. How does it compare to your prediction?
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