1. The problem statement, all variables and given/known data A cylinder of mass M and radius R rolls(without slipping) down an inclined plane whose incline angle with the horizontal is Θ. Determine the acceleration of the cylinder's venter of mass.(Derive the formula) 2. Relevant equations I have the answer, but I just don't understand: ∑τ=Iα, use the parallel-axis theorem and a=Rα. (Mg sin Θ)R=(1/2MR²+MR²)(a/R) Rg sin Θ=3/2Ra a=2/3g sinΘ 3. The attempt at a solution Here's my question. Why do we need to use the parallel-axis theorem? isn't that the torque is just 1/2MR² ? Maybe I am confused with the concept of Torque. I don't know...Please help!!!