Final answer:
The area of contact does not affect the amount of friction between two dry surfaces; instead, the frictional force depends on the normal force and the coefficient of friction.
Step-by-step explanation:
The factor that does not affect the amount of friction generated between two dry surfaces is the area of contact. Despite common misconceptions, the frictional force is proportional to the normal force and the coefficient of friction, but not to the total area of contact between the surfaces.
The reason for this is because the actual contact points are just the high spots on the surface, and those are the only areas where the friction force is actually applied. When a greater normal force is exerted, due to say, more mass being added to an object, the actual contact area increases, thereby increasing the friction force proportionally.
This is clearly demonstrated in physics where the force of friction (Ff) can be calculated using the equation Ff = μsN, where μs is the coefficient of static friction and N is the normal force. In a real-life scenario, like pushing a 100 kg crate across the floor, the normal force would be its weight, calculated by the equation w = mg, which equals 980 N for our crate example. This normal force has a significant impact on the frictional force that opposes the motion of the crate.