Final answer:
When a thin semicircular rod is broken into two halves, each half will have half the mass of the original and their centers of mass and moments of inertia will change due to the altered mass distribution.
Step-by-step explanation:
When a thin, semicircular rod is broken into two halves, the result will be two quarters of a circle. If the original rod was uniform in mass distribution, each half will have half the mass of the original rod. The center of mass for each half will no longer be at the center of the original semicircle but will move towards the center of the quarter-circle shape. Additionally, if the rod is broken while being used in a physics experiment related to rotation or oscillation, such as one involving moment of inertia or rotational dynamics, the mechanical properties will change. The moment of inertia, for example, would be different for each half relative to a chosen axis because the distribution of mass has changed.