Students suspend paper cups from different kinds of rubber bands attached to boards by means of tape and paper clips. They add pennies to the cups and measure how much the different rubber bands stretch. They graph their data and develop a formula relating stretch to mass. The extension has students compare rubber bands of different characteristics.
Students then stretch the rubber bands measured amounts, and let go.
They graph their data and discuss the results. In the extensions, students compare the behavior of different rubber bands, and devise a formula combining stretch and shoot formulas. Critique These lessons offer a number of exciting opportunities. Both lessons, however, put too much emphasis on measuring and recording. Students could make fuller observations, begin to develop a sense of what goes on when rubber bands stretch, and discuss the relationship of stretch to shoot qualitatively.