The force of friction on an object placed on an inclined surface depends on the angle of inclination, the weight of the object, and the coefficient of friction between the object and the surface. The force of friction acts opposite to the direction of motion or tendency of motion of the object.

The magnitude of the force of friction can be calculated using the equation:

Friction force = coefficient of friction x normal force

where the normal force is the force perpendicular to the surface that the object is resting on.

For an object placed on an inclined surface, the normal force is equal to the component of the weight of the object perpendicular to the surface. This can be calculated using the equation:

Normal force = weight x cos(theta)

where theta is the angle of inclination.

Once the normal force is determined, the force of friction can be calculated using the above equation.

The formula for determining the force of friction is defined as: