Answer:[tex]\mu_{k}[/tex]
Explanation:
We use kinetic friction when a body is moving i.e. [tex]\mu_{k}[/tex] for calculations.
Static friction is used when a body is in rest while kinetic friction is used when a body is moving and its value is quite low as compared to static friction .
Static friction value increases as we apply more force while kinetic friction occurs when there is relative motion between bodies.
