Q. A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1g and 3g. The total KE of the fragments is 6.4$\times 10^{4}$ J. what is the KE of the smaller fragment?
A) $2.5 \times 10^{4}$ J
B) $3.5 \times 10^{4}$ J
C) 4.8$\times 10^{4}$ J
D) $5.2 \times 10^{4}$ J
Explanation
(c) [image:7_image177.emf]
As the momentum of both fragments are equal therefore
$\frac{E_{1}}{E_{2}} = \frac{m_{2}}{m_{1}} = \frac{3}{1}$
$E_{1} = 3E_{2}$
According to problem
$E_{1} + E_{2} = 6.4 \times 10^{4}$J
By solving equation (i) and (ii) we get
$E_{1} = 4.8 \times 10^{4}$ J and
$E_{2} = 1.6 \times 10^{4}$J
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.