This lesson was developed in a Lesson Study Project over three years. The authors are Karen Vanderheyden, Markeeta Clayton, Nikki Grimes and John Graybill. They called this lesson–

“Send in the Reinforcements” You can download it here.

The lesson is the first in a series of explorations of the way members and joints distribute load in a bridge. The original idea came from a video on the Annenberg Foundation learner.org, which I highly recommend. We have been unable to locate the video clip of the original activity, although hopefully it is still there.

The beauty of this activity is that it allows students to “see” force vectors, at least their direction. Magnitude is represented by the thickness of the paper which transmits the force.