When a `U^(238)` nucleus originally at rest, decays by emitting an alpha particle having speed 'u' the recoiled speed of residual nucleus is:

Options

A. `(-4u)/(238)`
B. `(4u)/(238)`
C. `(-4u)/(234)`
D. `(4u)/(234)`

Answer

c

Explanation

The velocity of recoil is `upsilon=-(m)/(M).u`
`=-(4)/(234)xxu=(-4u)/(234)`
Hence choice is (c).