Final answer:
The coefficient of kinetic friction is influenced by surface roughness and is independent of the normal force; it is not reliant on the block's mass or the temperature directly.
Step-by-step explanation:
The coefficient of kinetic friction between a block and a surface is influenced by surface roughness and the materials in contact. It is a unitless value that depends on the nature of the two surfaces. According to the provided options, the coefficient of kinetic friction is:
- Depends on the block's mass: Incorrect, as the coefficient itself does not depend on mass.
- Influenced by the surface roughness: Correct, the roughness of the surfaces affects the coefficient.
- Affected by the temperature: Not mentioned, but temperature can affect the coefficient indirectly by changing the surface properties.
- Independent of the normal force: Correct, the coefficient itself is independent of the normal force as it is a ratio between the force of kinetic friction and the normal force.
Thus, the most accurate answer of the options provided is that the coefficient of kinetic friction is influenced by the surface roughness and is independent of the normal force.
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