Considering the yo-yo like two CDs with a hollow cylinder between them, what is the moment of inertia of that object?
The axis that I must choose can't pass through the CM and be parallel to rotational axis that passes through the center of mass. A force $\vec{T}$ is pulling the object.
I can't use the Steiner theorem here, right? All because that cylinder cannot be ignored.
Another try that I do is calculating the moment of inertia of the three (well, two) objects and sum, but I think that this isn't correct.
Best Answer
Use Steiner theorem and ignore the cilinder between the two disc.