Four masses m, 2 m, 3 m and 4 m are connected by a rod of negligible mass. The moment of inertia of the system about the axis AB is

Options

A. `52 ma^(2)`
B. `9 ma^(2)`
C. `50 ma^(2)`
D. `20 ma^(2)`

Answer

C

Explanation

`l=m_(1)r_(1)^(2)+m_(2)r_(2)^(2)+m_(3)r_(3)^(2)`
`= 2m(a^(2))+3m(4a^(2))+4m(9a^(2))`
`= 2ma^(2)+12ma^(2)+36ma^(2)`
`50 ma^(2)`.