Propeller Engines, Its a wind up! 
This product is endorsed by the London Science Museum. Build vehicles powered by the energy stored in stretched elastic. Propellers make use of the third law of motion "for every action ona na object there is an equal, but oppersite reaction". In other words, any force is balanced by another one in the oppersite direction. As the wound-up elasic unwinds itself it turns a propeller. The kit uses this motion to power a cart and a boat.
Contents?
For Ages 8 Years+
