How do we know when an object is in static or dynamic equilibrium?

First Condition of Equilibrium

Explanation:

This means that both the net force and the net torque on the object must be zero. The condition Fnet=0 F net = 0 must be true for both static equilibrium, where the object's velocity is zero, and dynamic equilibrium, where the object is moving at a constant velocity.The sum of the forces on it in each direction is zero. The sum of the torques on it in each direction is zero. Its linear momentum is zero.

One answer could be erosion