A hoop of mass M and radius R is hung from a support fixed in a wall . Its moment of inertia about the support is

Options

A. `2MR^2`
B. `3 M R^2`
C. `4 M R^2`
D. `6 M R^2`

Answer

A

Explanation

A hoop is a circular ring `therefore I_(0) = MR^(2)`
By theorem of parallel axes ,
`I = I_(0) + MR^(2) = MR^(2) + MR^(2) = 2 MR^(2)`