I am slipping off my spinning disc-- 1. The problem statement, all variables and given/known data I am taking a non calculus based physics class and have hit a wall with this one. I have a horizontal spinning disc with an Angular Acceleration of .25 rad/s^2 from rest. The disc has a radius of .05 m. A pebble is placed .025m from the center point of the disc and it has a coeff.of static friction of .15. How long will it take for the pebble to slip off the disc? And how many revolutions will the disc have rotated through that time? 2. Relevant equations Wi=Wf + alpha T. But since I can't get T or W I am stuck. If they had furnished a time or rpms or any other bones I could have gotten it. 3. The attempt at a solution I think centripetal acceleration is the key but again with out any W I am stuck. Help please.