A rigid body rotates with an angular momentum L. If its kinetic energy is halved, the angular momentum becomes,

Options

A. L
B. L/2
C. 2L
D. `L//sqrt(2)`

Answer

D

Explanation

K.E. `=1/2 (L^(2))/I`
`L^(2)=2K.E. I`
`L=sqrt(2K.E.I)`
`L prop sqrt(K.E)`
`Lprop sqrt(K.E)`
`L'prop sqrt((K.E.)/2)`
`(L')/L=L/(sqrt(2))`