Physics 2D friction problem

Hello everyone, I need help with physics 2D simulation. I have two objects with flat surfaces. Each have rigidbody 2D and collider 2D. One of them is placed on top of the second. When the lower object moves, the upper one is not affected at all. I need this two objects to act like this: a) if the lower one is moving slowly, the upper should remain on it and move with it; b) if the lower one changes position quickly, the upper one should fall and not follow it. Just like in real life. Adding physics material 2D and setting friction to higher values, didn’t help.