Question

A nucleus of mass number A, originally at rest, emits ana-particle with speed v. The daughter nucleus recoils with a speed-

• A. 2v/(A + 4)
• B. 4v/(A + 4)
• C. 4v/(A – 4)
• D. 2v/(A – 4)

Answer 1

Answer: (C)

4v/(A – 4)

Answer 2

m_av_a = m_Dv_D Ž v_D = $\frac{m_{\alpha}}{m_{D}}$v_a = $\frac{4}{A - 4}$v