THE LESSON: Building a small-scale bridge or tower and testing it on a shaking table helps show how real structures respond to an earthquake.

THE LESSON: Building a small-scale bridge or tower and testing it on a shaking table helps show how real structures respond to an earthquake.

Seventh-graders in an earth science class at Willow Wind Community Learning Center had 90 minutes to design and test simple structures that they hoped would withstand 20 seconds of shaking on a table that simulates a large-magnitude earthquake.

The construction materials, supplied by their teacher, Andy Strange, included 30 craft sticks, 4 feet of masking tape and a small ball of modeling clay.

Teams of two students brainstormed ideas and then made a tower or bridge. The structure was placed on the table. After a countdown of "5-4-3-2-1," the shaking began. Seconds were counted to mark the time when either the structure collapsed or it survived the 20-second experiment.

Observations and hypotheses were shared and then the next structure was tested.

The Willow Wind students now understand that engineering design is a process of identifying needs and constraints, defining problems, developing solutions and evaluating proposed solutions.

Student Kate Joss-Bradley says, "It was fun to have a hands-on project instead of just sitting around talking about building a bridge."

— Heidi Monjure