A circular hole of radius `r` is made in a disk of radius `R` and of uniform thickness at a distance `a` from the centre of the disk. The distance of the new centre of mass from the original centre of mass is

Options

A. `(aR^(2))/(R^(2)-r^(2))`
B. `(ar^(2))/(R^(2)-r^(2))`
C. `(a(R^(2)-r^(2)))/(r^(2))`
D. `(a(R^(2)-r^(2)))/(R^(2))`

Answer

B

Explanation

`x=(r^(2)a)/(R^(2)-r^(2))`