In the following figure, a sphere of radius 3m rolls on a plank. The accelerations of the sphere and the plank. The accelerations of the sphere and the plank are indicated. The value of `alpha` is

Options

A. `3 rad//s ^(2)`
B. `6 rad//s^(2)`
C. `3 rad //s^(2)` (opposite to the direction shown in figure)
D. `1 rad //s^(2)`

Answer

A

Explanation

`a_(1) =R alpha -a_(2)`
`3= 3 alpha -6`
`9=3 alpha`
`alpha =3 rad //s ^(2)`