In doing this activity with a large class, I had a group set up the scenario, but then I asked each table to consider the problem as if they were the group. I think it helped to streamline the group discussion. Once at least all of the major points were brought up (“how do you get a net momentum from nothing?”, difference in mass makes a difference, etc.), I brought the class together to think about it as a whole. Once we got to the fact that we need a line, I did a poll of where we should put the heaviest people - it was pretty mixed. At that point, I think it might have been a good idea to say, “find someone who disagrees with you and try to convince them.”

For the people that wanted to put the heavy people on the side of the food, their motivation was that this would move the center of mass closer to the food. One way this could be addressed would be to talk about a teeter totter. You can't move the pivot point, so how do you move the board so that the long side is near the food, but it is still balanced?

I think in the future, if I had a course this big, I would have each group actually try to do the activity and draw a diagram of what they would do and why - i.e. turn it into an actual survivor activity.