A solid sphere spinning about a horizontal axis with an angular velocity `omega` is placed on a horizontal surface. Subsequently it rolls without slipping with an angular velocity of :

Options

A. `(2omega)/(5)`
B. `(7omega)/(5)`
C. `(2omega)/(7)`
D. `omega`

Answer

C

Explanation

Initial sphere is slipping and finally it starts rolling during its motion `tau` about point of contact is zero.
Angular momentum of sphere about point of contact remains conserved.

`Iomega=(I+MR^(2))omega.`
`implies(2)/(5)MR^(2)omega=((2)/(5)MR^(2)+MR^(2))omega.impliesomega.=(2omega)/(7)`.