Q: Are the students allowed to use clay to attach the beaker to the span of the bridge? Or can they not do that because the bridge has to be measured before the beaker is placed?
A: Yes. Clay may be used to increase the stability of beaker on the bridge and we encourage the students to place the beaker on the bridge to ensure it will not slide off prior to calling their bridge "done". They must, however, remove the beaker for measuring and replace it prior to loading. Since the clay we use is not sticky, placing the beaker on the bridge to ensure stability and then removing the beaker should not affect the integrity of the bridge.