Scallops use muscles to close their shells. Opening the shell is another story—muscles can only pull, they can’t push. Instead of muscles, the shell is opened by a spring, a pad of a very elastic biological material called abductin. When the shell closes, the pad compresses; a restoring force then pushes the shell back open. The energy to open the shell comes from the elastic energy that was stored when the shell was closed. Figure P10.28 shows smoothed data for the restoring force of an abductin pad versus the compression. When the shell closes, the pad compresses by 0.15 mm. How much elastic potential energy is stored?

Restoring force (N) 2.5+ 2.0 1.5 1.0 0.5 0 0 0.05 0.10 0.15 0.20 Compression (mm) FIGURE P10.28