Two point masses of 0.3 kg and 0.7kg are fixed at the ends of a rod of length 1.4 m and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum, is located at a distance of

Options

A. `0.4 m` from mass of `0.3 kg`
B. `0.98 m` from mass of `0.3 kg`
C. `0.70 m` from mass of `0.7 kg`
D. `0.98 m` from mass of `0.7 kg`

Explanation

`M.I.` abou the center of mass is minimum, distance of `c.m.` from `0.3 kg`
`(0.7xx1.4)/(0.3+0.7)=0.98m`