Automated pulleys carrying load in a factory.
Step-by-step explanation:
Automated pulleys and ramps in a cement factory are usually in static equilibrium in that they are moving at a constant speed.
If they suddenly stop, the whole assembly line is bound to stop and the work gets stopped with the machine supposed to fill them dumping cement in the ground.
If they go too fast they run the risk of injuring employees or spilling over vast amount of load which can be dangerous.