A bomb of mass 3.0 Kg explodes in air int

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A bomb of mass $3.0\, Kg$ explodes in air into two pieces of masses $2.0 \,kg$ and $1.0\, kg$. The smaller mass goes at a speed of $80 m/s$.The total energy imparted to the two fragments is ............. $kJ$

A

$1.07$

B

$2.14$

C

$2.4$

D

$4.8$

A bomb of mass $3.0\, Kg$ explodes in air into two pieces of masses $2.0 \,kg$ and $1.0\, kg$. The smaller mass goes at a speed of $80 m/s$.The total energy imparted to the two fragments is ............. $kJ$

Both fragment will possess the equal linear momentum ${m_1}{v_1} = {m_2}{v_2}$ 

==> $1 \times 80 = 2 \times {v_2}$ ==> ${v_2} = 40\;m./s$  

Total energy of system$ = \frac{1}{2}{m_1}v_1^2 + \frac{1}{2}{m_2}v_2^2$ 

= $\frac{1}{2} \times 1 \times {(80)^2} + \frac{1}{2} \times 2 \times {(40)^2}$ 

$= 4800 J = 4.8 kJ$