Question

A uranium 238 nucleus, initially at rest emits n alpha particle with a speed of `1.4xx10^7m/s`. Calculte the rcoil speed of the residual nucleus thorium 234. Assume that the mas of a nucleus is proprotional to the mass number.

Answer 1

As uranium 238 nucleus emits alpha-particel with a speed of `1.4xx10^7` m/sec.
Let `v_2` be th speed of the residual nucleus thorium 234.
`m_1v_1=m_2v_2`
`rarr 4xx1.4xx10^7=234xxv_2`
`v_2=(4xx1.4xx10^7)/235`
`=2.4xx10^5 m/sec`