This activity involves direct experimentation of the phenomenon through manual skills and play. The scientific focus will be on the principle of action and reaction. Participants will be divided into small groups and will have to collaborate in the creation of a toy car with recycled materials, using the jet of air from a balloon as a propeller. A prototype and a project will be available and participants will be assisted in the construction by the animator where necessary.

Following the construction phase, it will be possible to experiment with the movement of the air-powered toy car and compare it with the jet rocket model. There will be a phase of reflection on the direction of movement of the toy car compared to the direction of the air jet.