* Gravité: Gravity pulls the ball downwards. On an inclined plane, this downward force is resolved into two components:one perpendicular to the plane (which is balanced by the normal force) and one parallel to the plane. This parallel component is the force that causes the ball to accelerate down the incline.

* Accélération: The force of gravity acting parallel to the incline causes the ball to accelerate. This means its speed increases as it rolls down.

* Energy Conversion: The ball gains kinetic energy (energy of motion) as it rolls down the incline. This energy comes from the potential energy it had at the top of the incline due to its position in the Earth's gravitational field.

en résumé: Gravity is the driving force behind a ball's acceleration down an inclined plane. The steeper the incline, the greater the component of gravity acting parallel to the plane, and the faster the ball will accelerate.