So, added mass force therefore, well added mass therefore, is a concept of force, not a mass. Lot of people thinks it is a mass attached to the body. No, there is no mass attached to the body, it is not sticking. First of all, it is based on potential theory. So, it cannot stick, it is only getting pushed in the normal direction, if I have a body here and I push it here, this water particle will get pushed this direction, not in this direction. Because it will have a velocity, this this it can allow you can allow it to slide, but you cannot allow this side; obviously, you cannot allow because if allowed to this side that would amount
to the fluid entering the fluid body you know. So, the normal relative velocity has to be 0.