A rod touches a disc kept on a smooth horizontal plane. If the rod moves with an acceleration `a`, the disc rolls on the rod without acceleration `a`, the disc rools on therod without slidding. Then , the acceleration of the disc w.r.t the rod is

Options

A. `a/3`
B. `(sqrt(3a))/2`
C. zero
D. `a//2`

Answer

A

Explanation

`ma cos theta-f=mAto(1)`
`fxxr=Ialphato(2),A =ralphato(3)`
From about equation `A=a/3`
`A=a/3` (where `theta=60^(@)& I=1/2mr^(2)`)