1. The problem statement, all variables and given/known data 2. Relevant equations I want to say I should be using this one: aA = aB + α x rA/B + ω x (ω x rA/B) 3. The attempt at a solution The only problem is that if I'm supposed to find the angular acceleration then i'd have to take the... inverse of the cross product? To get it back and I don't think that that's possible. I also want to say that it's zero because OQ moves with constant angular velocity, but I believe that that would result in PQ moving with acceleration because theta would be changing?