What is the actual 'mechanism' of friction

  1. in mechanics and physics we are forever talking about friction and using it to solve problems.

    but what actually is friction?

    is it as simple as saying how rough a surface is? that doesn't sound adequate to me.

    if that were the case then i'd expect all materials to have the same coefficient of friction if they were as flat as a mirror for example.

    i have a feeling that it probably has something to do with interactions between electrons on the surfaces of the two materials in contact.

    please can somebody describe the actual reason we feel a friction force.

    thanks.
     
  2. jcsd
  3. Roughness does play a part, but not the only part. I don't know about electrons, but as you suggest there are also intermolecular forces at play that determine friction.

    Ultimately there are many factors. Books have been written on the subject, and you're certainly not the only one who doesn't uderstand it. In fact, nobody fully does.
     
  4. I'm just taking a little bit of a wild stab at this, but I would assume that certain materials have a molecular adhesion or attraction which causes much more friction!
     
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