where r = 9in, and h = 2ft = 24in
From this volume, you are removing 1/4 of it. Thus, your final answer is
The above will give you cubic inches. You then need to convert to cubic meters.
1in = 0.0254m -->so multiply the answer you get above by this final conversion factor. One cubic inch is a tiny fraction of a cubic meter, this should make intuitive sense to you.