Q 11-05-014NEETJEE MainEAMCET 2014 (Engineering)Top questionMedium
A cannon shell fired breaks into two equal parts at its highest point. One part retraces the path to the cannon with kinetic energy $E_1$ and the kinetic energy of the second part is $E_2$. The relation between $E_1$ and $E_2$ is
Answer: (C) $E_2 = 9E_1$
Concept. Momentum conservation at the top (horizontal velocity $v$).
Step 1. Other part. $2mv = m(-v) + mv_2 \Rightarrow v_2 = 3v$.
Step 2. Energies. $\dfrac{E_2}{E_1} = 9$.
Answer. $E_2 = 9E_1$ (Option C).
Solution by Sreeraj P, M.Sc Physics