Two block `A` and `B` of masses `3m` and `m` respectively are connected by a massless and nextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of `A` and `B` immediately after the string is cut, are resectively

Options

A. `g,(g)/(3)`
B. `(g)/(3),g`
C. `g,g`
D. `(g)/(3),(g)/(3)`

Answer

B

Explanation

Before the string is cut
`kx=T+3mg` .......(1)
`T=mg` ........(2)

`implies kx= 4mg `
After the string is cut , T=0
`a=(kx-3mg)/(3m)`
`a=(4mg-3mg)/(3m)`
`a=(g)/(3) uarr `