Q 11-05-087JEE MainJEE Main 2024 (31 Jan, Shift 1)Easy
An artillery piece of mass $M_1$ fires a shell of mass $M_2$ horizontally. Instantaneously after the firing, the ratio of the kinetic energy of the artillery and that of the shell is:
Answer: (B) $\dfrac{M_2}{M_1}$
Both start from rest, so they get equal and opposite momenta $p$. With $K = \dfrac{p^2}{2M}$:
$$\frac{K_1}{K_2} = \frac{M_2}{M_1}$$
Solution by Sreeraj P, M.Sc Physics