Q. A nucleus of $\ _{84}Po^{210}$originally at rest emits an $\alpha$-particle with speed $v$. What will be recoil speed of the daughter nucleus?
A) $4v/206$
B) $4v/214$
C) $v/206$
D) $v/214$
Explanation
(a) Applying principle of conservation of linear momentum,
$m_{\alpha}v_{\alpha} +^{m}N^{v}N = 0$
$4v + (210 - 4)^{v}N = 0$
$\ ^{v}N = \frac{- 4v}{206}$
Negative sigh for recoil speed
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.