I’m taking an introductory course in thermodynamics right now and I have learned that in a quasi static process, one way to increase internal energy is to do work on a system or supply heat to it. But when you do work on a system, it increases its velocity- so how can it be in a state of equilibrium? For example, if I raise a block from one height to another height really slowly, its velocity is zero when it’s at the top because I’ve done negative work on it along with air resistance to stop it. So, how can work be done on a system without increasing its velocity such that it remains in equilibrium through every step?