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.KJ

Answer

D

Explanation

Velocity of second piece can be find out using consarvation of momentum.
O=`m_(1)v_(1)+m_(2)v_(2)`=`2xxv_(1)+1xx80`implies` v_(1)=-40 m//s.`
Negative sign showing that particle is moving in opposite direction of other particle direction.Energy imparted to the fragments are converted into their kinetic energy.
`therefore` Total energy`=(1)/(2)m_(1)v_(1)^(2)+(1)/(2)m_(2)v_(2)^(2)`
`(1)/(2)xx2xx1600+(1)/(2)xx1xx6400`
4800 J=4.8 KJ.