Question

Two identical rings each of mass m with their planes mutually perpendicular, radius R are welded at their point of contact O. If the system is free to rotate about an axis passing through the point P perpendicular to the plane to the paper, the moment of inertia of the system about this axis is equal to

A. `6.5mR^(2)`
B. `12mR^(2)`
C. `6mR^(2)`
D. `11.5mR^(2)`

Answer 1

`I=I_(1)+I_(2)=[2mR^(2)]+[(mR^(2))/(2)+m(3R)^(2)]`
`=11.5mR^(2)`