Question

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). If the ice melts, by what distance does the centre of mass of "the tray plus the ice" system descend?

Answer 1

As the hall is gravity free i.e no gravitational force acts on the water drops. Now, as the ice melts, the water drops acquire the spherical shape due to the surface tension.. But there is no external force acting on the system. So, the center of mass of the system would not move.