Final answer:
The static frictional force is independent of surface area, increases linearly with normal force, and is dependent on the materials in contact.
Step-by-step explanation:
From the given information, we can address the student's question regarding static frictional force's dependence on various factors as follows:
- Surface area: Static frictional force does not vary inversely with surface area. Rather, friction is independent of the surface area in contact because the actual contact area is just a tiny fraction of the total area, consisting of only the high spots that touch.
- Normal force: The frictional force increases linearly with the normal force. When a greater normal force is exerted, the actual contact area increases and friction is found to be proportional to this actual contact area.
- Materials: Frictional force is dependent on the material making up the two surfaces in contact. The coefficient of friction, which determines the frictional force, is a property that depends on the nature of the materials.
Additionally, the data in step C2 does not directly address the dependence on materials. However, we understand from broader concepts that the material does have an impact on the magnitude of friction.