1. The problem statement, all variables and given/known data An disk has a radius of 0.2 meters. A lump of putty with a coefficient of static friction of 0.9 is stuck on the edge of the disk. Let's say the disk starts at rest and gradually speeds up. At what speed will the putty just barely be able to stay in place on the edge of the disk? 2. Relevant equations ac=v^2/r at=(v-vi)/t Fs=M*N 3. The attempt at a solution I'm a bit stuck as to where I should start with this.