Inclined plane - Sliding

A box placed on an inclined plane is subject to several forces: the gravitational force (weight), the normal force (reaction of the support), and the force of friction. The gravitational force can be broken down into two components: one parallel to the inclined plane, which pushes the object downwards, and one perpendicular to the inclined plane, which is balanced by the normal force exerted by the surface of the plane. The angle of inclination of the plane modifies the intensity of these forces and therefore the object's behavior.

Friction plays a crucial role in the object's movement on the inclined plane. There are two types of friction:

• Static friction is the frictional force that prevents an object from moving.
• Kinetic (or dynamic) friction is the friction force measured when the object is in motion.

On a rough surface such as concrete, the coefficients of friction (static and kinetic) are greater than on an icy surface, which further opposes movement and delays the object's sliding. On the other hand, on a smooth surface like ice, the coefficients of friction (static and kinetic) are much lower, facilitating sliding and acceleration.

To sum up, balancing an object on an inclined plane requires a good representation of the forces involved in an appropriate axis system, and an understanding of how the angle of the plane and the type of surface influence the forces.