A thin disc of mass 9M and radius R from which a disc of radius R/3 is cut shown in figure. Then moment of inertia of the remaining disc about O, perpendicular to the plane of disc is -

Options

A. `4MR^(2)`
B. `9 MR^(2)`
C. `37/9MR^(2)`
D. `40/9MR^(2)`

Answer

A

Explanation

`I=(9M(R^(2)))/2-{M(R/3)^(2)+M((2R)/3)^(2)}`
`=4MR^(2)`