A binary star consist of two stars A (2.2 Ms) and B(mass 11Ms) where Ms is the mass of sun. They are separated by distance d and are rotating about their centre of mass, which is stationary. The ratio of the total angular momentum of the binary star to the angular momentum of star B. about the centre of mass is
Here C.M wrt A $ = \left( { 11M_5 \over 11M_5 + 2.2 M_5 } \right) d = {5d \over 6 } $ $ L_A = 2.2 M_5 w \left( { 5d \over 6} \right) ^2 = 55M_5 w { d^2 \over 36 } $ $L_B = 11 M_5 \omega \left( { d \over 6} \right)^2 = 11 M_5 \omega { d^2 \over 36 } $