Q. When $U^{238}$nucleus originally at rest, decays by emitting an alpha particle having a speed u The recoil speed of the residual nucleus is
A) $\frac{4u}{238}$
B) $- \frac{4u}{234}$
C) $\frac{4u}{234}$
D) $- \frac{4u}{238}$
Explanation
(c) [image:6_image103.jpeg]
Apply conservation of linear momentum.
$0 = 4u - 234v$
$\Rightarrow v = \frac{4u}{234}$
The residual nucleus will recoil with a velocity of $\frac{4u}{234}$ unit.
Recoil speed of residual nucleus is $\frac{4u}{234}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.