I am trying to understand the physical concept of friction in terms of Aristotle's efficient cause. This is not a physics question.
Friction is said to be caused by the electromagnetic force between the surface molecules of two objects. But it is also said to be caused by the force exerted by asperities of the two surfaces on each other. (An asperity can be defined as follows: when you zoom into a surface, no matter how smooth, at the molecular level there are tiny prominences on the surface because it is not perfectly smooth at the molecular level, and these prominences are called asperities.)
When the asperities of two objects are attracted due to close contact, when you try to push one of them away from the other it takes a bit of force to disconnect their attraction. This attraction is what causes friction.
After reading this description of friction I got a bit confused. Is the efficient cause of friction the electromagnetic force or the force between the asperities? I am aware that they are basically the same thing: the electromagnetic force is what causes the force between the asperities on the surfaces of the two objects.
However, what I am unsure about is how I would answer a question such as, "What is the efficient cause of friction between two objects?" Should I say "it is caused by the electromagnetic force between their surface molecules", or "it is caused by the electromagnetic force between the asperities on the surfaces" or "it is caused by the force between the asperities on the surfaces" (omitting "electromagnetic")?
I think my question is more about: How do I achieve crystal clarity when asking and answering questions, so that the answer exactly answers the question? There seem to be many different ways of answering the same question.
Is there a method for removing this ambiguity by wording the question differently?