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 :

Options

A. `1.07` kJ
B. `2.14 kJ `
C. `2.4` kJ
D. `4.8 ` kJ

Answer

B

Explanation

Conservation of linear momentum
`3(10) = 2v + 1 (80)`
`2v = - 80`
`v = - 40m//s `
Total K.E ` = 1/2 m_(1)v_(1)^(2) +1/2m_(2)v_(2)^(2)`
`=1/2 xx2xx40^(2)+1/2 xx1xx(80)^(2)`
= 4800 J = 4.8 kJ