A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg . The velocity of 18

Question

A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg . The velocity of 18 kg mass is $6 \mathrm{~m} \mathrm{~s}^{-1}$. The kinetic energy of the other mass is\

Professor PC Thomas Classes · Answer

(b) : According to law of conservation of linear momentum, $$ 30 	imes 0=18 	imes 6+12 	imes v $$ $\Rightarrow-108=12 v \Rightarrow v=-9 \mathrm{~m} / \mathrm{s}$.\ Negative sign indicates that both fragments move in opposite directions.\ K.E. of $12 \mathrm{~kg}=\frac{1}{2} m v^{2}=\frac{1}{2} 	imes 12 	imes 81=486 \mathrm{~J}$\