A thin circular ring of mass `m` and radius `R` is rotating about its axis with a constant angular velocity `omega`. Two objects each of mass `M` are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity `omega' =`

Options

A. `(omega (M-2m))/(M + 2m)`
B. `(omega M)/(M + 2m)`
C. `(omega M)/(M + m)`
D. `(omega (M + 2m))/(M)`

Answer

B

Explanation

`L_(i) = (Mr^(2)) omega, L_(f) = (Mr^(2) + 2mr^(2)) omega.`
`L_(i)= L_(f) rArr omega.= (M omega)/(M + 2m)`