It is my understanding that static friction between two surfaces arises at least partly due to inter-molecular forces, e.g. Van der Vaals forces.
The question: Consider this scenario: If I push a box, let it go, and the box slides up a ramp, its velocity will become zero at some point, due to gravity, and then the box will slide down. At that point, when velocity became zero, will static friction have come into play? (E.g. will the gravitational force in the direction down the ramp have to exceed the static friction force?)
My thoughts: Intuitively I would argue yes, but my philosophical problem with it is that, at least mathematically speaking, the box was at that point only an infinitesimal amount of time; how could bonds be formed in that amount of time?
As an extension to the question, whose answer I'm guessing is that there's indeed enough time for bonds to form; is there ever any situation where there is not enough time for such bonds to form, despite having zero velocity at some point? (E.g. a box pushed up with a very strong force on a planet with a very strong gravitational force, so that the change of velocity occurs more quickly.)
Thanks in advance!