Question

A body A of mass M falling vertically downwards under gravity breaks into two part; a body B of mass $\frac{M}{3}$ and a body C of mass $\frac{2}{3}$ M. The COM of bodies B and C taken together shifts compared to that of body A towards :

• A. depends on height of breaking.
• B. does not shift.
• C. body C.
• D. body B.

Answer 1

Answer: (B)

does not shift.

By Newtons second law for system of bodies, $F_{external}=m{a}_{CM}$. This equation does not involve internal forces between bodies. SInce in this case, no horizontal force exists on the system of two parts and hence COM will not shift.