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\includegraphics[max width=\textwidth, alt={}, center]{7800deca-98e8-4eb4-9176-288bb1f44fec-06_351_607_269_769} An object is made from a uniform solid hemisphere of radius 0.56 m and centre \(O\) by removing a hemisphere of radius 0.28 m and centre \(O\). The diagram shows a cross-section through \(O\) of the object.

1. Calculate the distance of the centre of mass of the object from \(O\).
   [0pt] [The volume of a hemisphere is \(\frac { 2 } { 3 } \pi r ^ { 3 }\).]
   The object has weight 24 N . A uniform hemisphere \(H\) of radius 0.28 m is placed in the hollow part of the object to create a non-uniform hemisphere with centre \(O\). The centre of mass of the non-uniform hemisphere is 0.15 m from \(O\).
2. Calculate the weight of \(H\).