Instruct other students in the same group to change one variable, repeat the procedure, and average the distance of the jumps. Students may vary the model by adding one or more rubber bands, adding more books to change the angle of the board, substituting the brick for the box, or using sandpaper of a different grit. If time allows, give every student a chance to operate the model with each of the variations. Ask students to complete their data sheets. Emphasize that different faults can store different amounts of energy before they fail.
Some faults have the potential for generating larger earthquakes than others.