The frictional force that occurs in dynamic friction is called "kinetic friction". When the force applied to an object is greater than the maximum static friction, the object begins to move. After it starts to move, if the applied force is reduced, the object stops moving again. This situation shows that after the object moves, there is still a force that prevents the object from moving, that is, there is still friction resistance. The frictional force generated when this object moves is called kinetic friction.

Dynamic friction: F_k=μ_k*N

here:

μ_k = Dynamic friction factor

N = Normal force