static friction VS kinetic friction

tyre同road係static friction 係因為佢地無relatively motion
e.g.個tyre同road接觸果點係靜止的

個pad同個disc係kinetic friction因為佢地都有relatively motion
e.g. 個disc都係轉緊的

如個press too hard,
disc會suddenly stopped, no more relatively motion
sliding出現因為due to inertia of the car