Thanks for the method, I built something like that before but I didn't know how to do the intermediary steps to have the good distance of friction. First, I would like to precise the word "slip", I'm focus on the friction (for the example with the friction), so for me, the word I used at start is a slip in the friction, I mean less distance in friction. I see for you, the slip is the distance of friction. It depends on what we are focused. For me, the distance d1-d2 is a lack of friction. Just to precise.
I try to build the drawings, but I have a problem in the steps in need to do because I need to built with some steps in the drawings to have the cases you described.
So, for me, I start with the drawing with the start and the end positions:
I glue the circle and the red wall together of the end position and I rotate to have the angle of the wall at start, I move them to have the wall at the end position at the same place than the start position, I have that:
What I need to do now ? I move the circle alone in translation (x and y) to be at the position of the circle at start ? And I don't rotate it ? In that case the distance measured is d2.
If I rotate the circle after repositionning it like before, I have d1:
If I don't repositionnate the circle before rotating, I have d1-d2: