A) \[2kg\]
B) \[1.2kg\]
C) \[3kg\]
D) \[1.5kg\]
Correct Answer: B
Solution :
Conservation of linear momentum gives \[{{m}_{1}}{{u}_{1}}+{{m}_{2}}{{u}_{2}}={{m}_{1}}{{v}_{1}}+{{m}_{2}}{{v}_{2}}\] \[\Rightarrow \] \[{{m}_{2}}{{v}_{2}}=\frac{3u}{2}\] ? (ii) Conservation of kinetic energy gives \[\frac{1}{2}{{m}_{1}}u_{1}^{2}+\frac{1}{2}{{m}_{2}}u_{2}^{2}=\frac{1}{2}{{m}_{1}}v_{1}^{2}+\frac{1}{2}{{m}_{2}}v_{2}^{2}\] \[\Rightarrow \] \[{{m}_{2}}v_{2}^{2}=\frac{15{{u}^{2}}}{8}\] ? (ii) Hence, on solving Eqs. (i) and (ii), we get \[{{m}_{2}}=1.2kg\]You need to login to perform this action.
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