A) 5 kg
B) 7 kg
C) 17 kg
D) 3 kg
Correct Answer: A
Solution :
[a] Apply law of conservation of linear momentum. Momentum of first part \[=1\times 12=12\,kg\,m{{s}^{-1}}\]. Momentum of the second part \[=2\times 8=16\,kg\,m{{s}^{-1}}\]. Resultant momentum \[=\sqrt{{{(12)}^{2}}+{{(16)}^{2}}}=20\,kg\,m{{s}^{-1}}\]. The third part should also have the same momentum. Let the mass of the third part be M, then \[4\times M=20\Rightarrow M=5\,kg\]You need to login to perform this action.
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