Includes activity sheets with 22 achievable experiments.

Topics covered

The meaning of words
Force, a primitive concept
Forces in contact and forces at a distance.
- Plastic materials and elastic materials
- A force in contact: the elastic force
- A force at a distance: weight
The effects of the forces
Active and passive forces
How to compare forces
- A property of elastic bodies: from qualitative to quantitative
The dynamometer
Vector representation of forces
The center of gravity
- When a body falls freely
The weight does not remain constant.
Heavy or light bodies: which one falls first?
The origin of weight and the force of gravity.
Why doesn't the moon fall to Earth?