Question

β - particle is emitted from the nucleus of mass number A with velocity u. Then, the recoil speed of the nucleus will be

• A. $\frac{vm_{e}}{A - m_{e}}$
• B. $\frac{vm_{e}}{A + m_{e}}$
• C. $\frac{4v}{A - 4}$
• D. $\frac{v}{A}$

Answer 1

Answer: (A)

$\frac{vm_{e}}{A - m_{e}}$

Answer 2

v. m_e= (A - m_e)v' or v' = $\frac{vm_{e}}{A - m_{e}}$