1. The problem statement, all variables and given/known data A grindstone, initially at rest, is given a constant angular acceleration so that it makes 20.0 rev in the first 8.00 s. What is its angular acceleration? (a) 0.313 rad/s2 (c) 2.50 rad/s2 (e) 3.93 rad/s2 (b) 0.625 rad/s2 (d) 1.97 rad/s2 2. Relevant equations Rotational Kinematic equations 3. The attempt at a solution Ok so I am using the equation ω = ω (initial) + ∝ T BUT my answer is the wrong one. It seems that I have to use this equation ω^2 = ω (initial) ^2 + 2∝Θ but what do I put in liew of "Θ"?????? I just don't understand why is that I have to use that equation?