A) \[12\text{ }m{{s}^{-1}}\]opposite to heavier mass
B) \[12\text{ }m{{s}^{-1}}\] in the direction of heavier mass
C) \[\text{6 }m{{s}^{-1}}\] opposite to heavier mass
D) \[\text{6 }m{{s}^{-1}}\] in the direction of heavier mass
Correct Answer: A
Solution :
The ratio of masses \[=1:3\] Therefore, \[{{m}_{1}}=x\,kg,\,\,\,{{m}_{2}}=3x\,\,kg\] Applying law of conservation of momentum \[{{m}_{1}}{{v}_{1}}+{{m}_{2}}{{v}_{2}}=0\] \[\Rightarrow \] \[x\times {{v}_{1}}+3x\times 4=0\] \[\Rightarrow \] \[{{v}_{1}}=-12m/s\] Therefore, velocity of lighter mass is opposite to that of heavier mass.You need to login to perform this action.
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