the question is: A disk of mass M and radius R unwinds from a tape wrapped around it. the tape passes over a frictionless pulley, and a mass m is suspended from the other end. assume that the disk drops vertically. 1. relate the acclerations of m and the disk, a and A, respectively to the angualr accelration of the disk. (the answer clue reveals that the naswer is: if A=2a, then alpha=3A/R. my answer is that the accleration of the disk equals -a+[tex]\alpha[/tex]R=A and then i get that if A=2a then alpha equals 3a/R, but it's the opposite it should be 3A/R, which i don't see how to arrive at this. anyway, in the attached file there's a pic of this, the above left pic. thanks in advance.