Instruct two students to sit on identical carts and give them each one end of a long rope. The students can either push off each other directly or pull towards each other by tugging on the rope. Similar results occur when only one student pushes/pulls. In both cases, the apparatus demonstrates the symmetry of forces and conservation of momentum.
Make sure carts have a smooth surface to roll on. If the room has rough flooring or carpeting, using smooth plywood or masonite as an intermedium works well.
Note: Standing works the same as sitting. Stand at your own risk.
Location: B Back Wall