posted by marwan .
Consider a square ABCD of side 10cm and total mass 10kg. Let O be the center of the sqaure. We cut a square of corners O and C.
Find the central mass of the obtained shape after removing the small cutten sqaure.
How big is the cut-off piece? You would need to that it most cases. (Not this time, however)
I think they want the Center of Mass, not the "Central Mass" -- whatever that is.
You also probably meant "off corners A and C" instead of "of corners O and C". There IS no corner at O. Please be more precise with your problem copying.
In this case, because of the symmetry of removing opposite corners A and C, the center of mass will not move.
Lets do it the math way.
now, doing it in each coordinate.
check all that.