The discussion revolves around determining the axis of rotation for a problem related to the moment of inertia, specifically problem #21. Participants are exploring the application of the parallel axis theorem in this context.
Some participants have provided guidance on using the parallel axis theorem and clarified that Icm refers to the inertia from the previous problem. There is ongoing exploration of the definitions and values for D and M, with no explicit consensus reached yet.
Participants are working under the assumption that the axis of rotation is through the tip of the arrow in the provided diagram. There may be uncertainties regarding the total mass and the specific distance used in calculations.
muna580 said:I am having trouble with #21. I already did #20, but I have NO idea of how to do #21. First of all, I am not really sure where is the axis suppose to be.
muna580 said:Acorrding to the parallel axis theorem, you get the inertia by dong this
I = Icm + D^2M
Where Icm is the inertia with respect to the center, and D is the distnance, and M is the mass.
Well, Icm is the answer I got for #20 right?
Also, what do I use for the D? Is D the radius?
Also, what is M? Is M the mass for the hoop plus the mass of all the 4 spokes?