Question

Two homogeneous spheres `A and B` of masses `m and 2 m` having radii `2 a` and `a` respectively are placed in contact. The ratio of distance of c.m from first sphere to the distance of c.m from second sphere is :

Answer 1

Correct Answer - `(2)`
Assuming that masses of the two spheres are concentrated at their centres `A` and `B` and taking `x = 0 at A`, Fig. we get
`x_(cm) = (m xx 0 + 2m xx 3a)/((m + 2m)) = 2a = AC`
`CB = a :. (AC)/(CB) = (2a)/(a) = 2`