Hi everyone, I have just started the chapter in my Physics book that deals with calculations of Moments of momentum for various extended bodies. I have come across a problem which involves, as part of the overall problem, finding the moment of momentum of the centre of mass of the object and axis, and I am confused as to how I calculate this term. The overall problem is as follows :- A uniform bar has 2 small balls glued to it's ends. The bar is 2.00 m long and has mass 4.00 kg, while the balls each have mass 0.500 kg and can be treated as point masses.Find the moment of inertia of this combination about the following axes. a) an axis perpendicular to the bar through it's centre b) an axis perpendicular to the bar through one of the balls c) an axis parallel to the bar through both balls d) an axis parallel to the bar and 0.500 m from it now I have successfully completed parts a), b) and c) above, but for part d) I decided to use the 'Parallel Axis Theorem to solve it .. The equation I used was .. I = I(cm) + M d(squared) where I(cm) is the moment of inertia of the centre of mass of the bar and axis, M is total mass of bar and balls, d is distance from bar to axis My problem is that I am not sure how to work out 'I(cm)' in this case. Can anyone help give me an explanation of how to work this value out or let me know if there is an alternative method of solving the problem ?