1. The problem statement, all variables and given/known data The ropes in the figure are each wrapped around a cylinder, and the two cylinders are fastened together. The smaller cylinder has a diameter of 10 cm and a mass of 5.0 kg; the larger cylinder has a diameter of 20 cm and a mass of 20 kg. What is the angular acceleration of the cylinders? Assume that the cylinders turn on a frictionless axle. I know the answer is 3.5 rad/s2. Figure: http://session.masteringphysics.com/problemAsset/1176936/5/P7-59.jpg 2. Relevant equations [itex]\alpha[/itex]=τ/I τ=rF I=1/2*M*R2 3. The attempt at a solution I tried calculating the net torque of the cylinders caused by the hanging masses. I then divided the net torque by the total inertia on the cylinders using the first equation listed above.