Two students stand on carts and pull (rope) or push (pole) each other. Used to demonstrate Newton's Third Law.

Setup Requirements: Minimal

Equations: Forces are equal in size but opposite in direction.

Safety Issues: Students may fall off carts.

Fan blows air one way. Cart goes the other way. Experiment with barrier blocking air stream with cart on air track. Fan provided may not be same as the one in the picture

Setup Requirements: Minimal. May need to replace batteries.

Equations: Forces are equal in size but opposite in direction. Momentum is conserved. Change in momentum of small particles hitting heavy barrier = 2 x initial momentum.

Safety Issues: Being cut by fan blade.