Consider a gravity-free hall in which a tray of mass M, carrying a cubical block of ice of mass m and edge L, is at rest in the middle (figure 9-E4). If the ice melts, by what distance does the centre of mass of “the tray plus the ice” system descend?
It is given that the hall is gravity-free and the block of ice is at rest. This implies no external forces are acting on the block. Therefore, the centre of mass of the system will stay the same.
The distance by which the centre of mass of the system descends = 0
1