Rotational Motion: The Relationship Between Linear and Angular Displacement

[ehabmozart]

Suppose a mass attached to a rope which winds around a rim or a disk. If the mass attached to the string falls x meters, should the string also move thorugh x meters around the rim or the disk which we can relate by s = r theta?

 

[HallsofIvy]

Yes, it pretty much has to doesn't it? That "x" distance has to come from somewhere!